Overlay 1

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 32 33 34 35 36 38 39 40 41 42 43 44 45 46 47 48 49 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 101-104 105 106 107 108 109 110 111 112 113 115 116 118 119 120 121 122 123 124 125 126 128 129 130 131 132 135 136 137 138 139 140 141 142 144 146 151 152 153 154 155 156


IOp(1/5)

L103: Mode of optimization.
0                  Find local minimum.
1                  Find a saddle point.
N                 Find stationary point on the energy surface with N negative eigenvalues of the 2nd deriv. matrix.

L107: Mode of search.
0                 Locate the maximum in the LST path.maximum in the LST path.
1                 Scan the LST path.

IOp(1/6)

L102, L103, L105, L107, L109, L113, L114: Maximum number of steps (or number of steps for an LST scan).
0                 NSTEP = Max(20,NVAR+10) (L103)
                                = Min(20,NVAR+10) (L102, L105, L109)
                                = Min(40,NVAR+20) (L113, L114)
N                 NSTEP = N

IOp(1/7)

L103, L105, L109, L112, L113, L114: Convergence on the first derivative and estimated displacement for the optimization, RMS first derivative < ConvF, RMS Est. Displacement < ConvX=4*ConvF. For L123, similar convergence control for the GS integrator.
-1                ConvF = 1/600 Hartree/Bohr or Radian
0                 ConvF = 0.0003 Hartree/Bohr or Radian
N                ConvF = N*10-6

L116, L117: Convergence on electric field/charges.
-1                Default value for optimizations: 10-7.
0                 Default value for single-points: 10-5 in L116, 10-7 in L117.
N                10-N.

IOp(1/8)

L103, L109, L112: Maximum step size allowed during Opt.
0                 DXMAXT = 0.1 Bohr or Radian (L103, Estm or UnitFC).
                                     = 0.3 Bohr or Radian (L103, Read or CalcFC).
                                     = 0.2 Bohr or Radian (L105).
                                     = 0.3 Bohr or Radian (L113, L114).
N                DXMAXT = 0.01 * N

L117: General control.
0                 Which type of basin to use to partition the density isosurface. Default is 4.
1                 GradVne.
2                 GradRho.
3                 Don't Use Basins, Use only the Center of Nuclear Charge.
4                 Use Interlocking Spheres.
N0              Order of Adam's-Bashforth-Moulton (ABM) predictor-corrector method to use in solving diff. eqns. for the grad RHO or                    Vne trajectories. Default is 4, max is 9.
N00            Number of small steps per ABM step to be used in starting ABM and when "slow down" is needed in ABM. Default is 5.
N000          Which approximation to make. Default is III for Tomasi (interlocking spheres) and IV for general surface.
1000           Apprx. I – Don't Do Self-Polarization or "Compensation"
2000           Apprx. II – Do Self-Polarization, But No Compensation.
3000           Apprx. III – Do Self-Polarization and Compensation.
4000           Apprx. IV – Do III and Allow Surface To "Relax" in Solution if no spheres ...
N0000        Whether to evaluate densities using orbitals or density matrix. Default is to use density.
10000         Use MOs.
20000         Use density.

L121: Time step, N*0.0001 fs, default 0.1.

IOp(1/9)

L103: Use of Trust radius.
0                 Whether to update trust radius (DXMaxT, default Yes). Default is Yes for minima, no for TS.
1                 No.
2                 Yes.
00               Whether to scale or search the sphere when reducing the step size to the trust radius. Default search for minima, scale for                    transition states.
10               Scale.
20               Search.

L106: Whether to use symmetry to reduce the number of L110 displacements.
0                 Yes.
1                 No.

L107: Whether to maintain symmetry along the search path.
0                 Yes.
1                 No.

L117: Whether to delete points which are too close together, and how close to get to the iso surface in search.
0                 No; Approx. 1.0 D-6 (N=20)
1                 Yes, using a default criterion (0.05 Angstroms).
-N              Yes, using a (10-N Angstroms) criteria: 2.0-N.

L121: Whether to read in initial velocities.
0                 Default (same as 1).
1                 Generate random initial velocity.
2                 Read in initial Cartesian velocity (Bohr/sec).
3                 Read in initial MW Cartesian velocity (sqrt(amu)*Bohr/sec).

IOp(1/10)

L103, L105, L109, L112, L113, L114: Input of initial Hessian: All values must be in atomic units (Hartree, Bohr, and radians).
0                 Use defaults (not valid for L109).
1                 Read ((FC(I,J),J=1,I),I=1,NVAR) (8F10.6) (L103 only).
2                 Read I,J,FC(I,J) (5I3,F20.0) (L103 only). End with a blank card.
3                 Read from checkpoint file in internal coordinates.
4                 Second derivative matrix calculated analytically. (Not valid for L109).
5                 Read Cartesian forces and force constants from the checkpoint file are converted to internal coordinates.
6                 Read Cartesian forces followed by Cartesian force constants (both in format 6F12.8) from input stream, followed by a                    blank line.
7                 Use semi-empirical force constants.
8                 Use unit matrix (default for L105; only recognized by 103).
9                 Estimate force constants using valence force field.
10               Use unit matrix throughout.

IOp(1/11)

L103: Test of curvature. Bomb the job if the second derivative matrix has the wrong number of negative eigenvalues.
0                 Default (Test for z-matrix or Cartesian TS but not for LST/QST or for minimum).
1                 Don’t test.
2                 Test.

L117: Step size for ABM method in Trudge for isodensity method.
0                 0.05 (N=2).
N                0.1/N.

IOp(1/12)

L103: Optimization control parameters.
0                 Use default values.
1                 Read in new values for all parameters (see INITBS).

IOp(1/13)

L103, L113, L114, L115, L123: Type of Hessian Update.
0                 Default (9 for L103 minimization, 7 for L103 TS, D2Corr and L115, Powell for L113 and L114, Bofill in L123).
1                 Powell (not in L103).
2                 BFGS (not in L103).
3                 BFGS, safeguarding positive definiteness (not in L103 or L115).
4                 D2Corr (New, only in L103 and L115).
5                 D2Corr (Old, only in L103 and L115).
6                 D2Corr (BFGS).
7                 D2Corr (Bofill Powell+MS for transition states).
8                 D2Corr (No update, use initial Hessian).
9                 D2Corr (New if energy rises, otherwise BFGS).

L121: Multi-time step parameter (NDtrC,NDtrP).
0                No multi-time stepping.
NN            Iterate density constraints NN times per step.
MM00       Do gradient once every MM steps.

L123: Hessian update.
0                 Default (Bofill).
1                 Murtagh-Sargent (SR1) update.
2                 Powell-symmetric-Broyden (PSB) update.
3                 Bofill's update.
4                 Sqrt(Bofill) update.
5                 No update (keep old Hessian).

IOp(1/14)

L103: Maximum number of bad steps to allow before doing a linear minimization (i.e., no quadratic step).
-1                0.
0                 Default (0 for TS, 1 for minima).
N                Allow N -- linear only starts with the N+1st.

IOp(1/15)

L103, L109: Abort if derivatives too large.
-1 or 0        No force test at all.
N                FMAXT = 0.1 * N.

IOp(1/16)

L103, L113, L114: Maximum allowable magnitude of the eigenvalues of the second derivative matrix. If the limit is exceeded, the size of the eigenvalue is reduced to the maximum, and processing continues.
0                EIGMAX = 25.0 Hartree / Bohr2 or Radian2
N               EIGMAX = 0.1 * N

IOp(1/17)

L103, L113, L114: Minimum allowable magnitude of the eigenvalues of the second derivative matrix. Similar to IOp(16).
0                EIGMIN = 0.0001.
N               EIGMIN = 1. / N.

IOp(1/18)

L103: Coordinate system.
0                Proceed normally
1                Second derivatives will be computed as directed on the variable definition cards. No optimization will occur.
10              Do optimization in Cartesian coordinates.
20              Do full optimization in redundant internal coordinates.
30              Do full optimization in pruned distance matrix coordinates.
40              Do optimization in z-matrix coordinates.
50              Do full optimization in redundant internal coordinates with large molecular tools.
100            Read the AddRedundant input section for each structure.
1000          Do not define H-bonds (default).
2000          Define H-bonds with no related coordinates.
3000          Define H-bonds and related coordinates.
10000        Reduce the number of redundant internals.
20000        Define all redundant internals.
100000      Old definition of redundant internals.
0000000    Default (2000000).
1000000    Skip MM atoms in internal coordinate definitions and do microiterations the old way, in L103.
2000000    Include MM atoms in internal coordinate definitions (no microiterations).
3000000    Skip MM atoms in internal coordinate definitions and do microiterations the new way, in L120.
4000000    Microiterations for pure MM, done in L402.

IOp(1/19)

L103: Search selection,
0                Default (same as 6).
2                Linear and steepest descent.
3                Steepest descent and linear only when essential.
4                Quadratic if curvature is correct; RFO if not. Linear as usual.
5                Quadratic if curvature is correct; RFO if not. No linear search.
6                RFO and linear.
7                RFO without linear.
8                Newton-Raphson and linear.
9                Newton-Raphson only.
10              GDIIS and linear.
11              GDIIS only.
13              First-order simultaneous optimization.
15              GEDIIS.
17              FOSimult with fixed geometry, for debugging.

L113, L114: Search Selection.
0                P-RFO or RFO step only (Default).
1                P-RFO or RFO step for “wrong” Hessian otherwise Newton Raphson.

IOp(1/20)

L101, L106, L108, L109, L110: Input units.
0                Angstroms degrees.
1                Bohrs degrees.
2                Angstroms Radians.
3                Bohrs Radians.

IOp(1/21)

L103, L113, L114: Expert switch.
0                Normal mode.
1                Expert mode. Certain cutoffs used to control the optimization will be relaxed. These include FMAXT, DXMAXT,                   EIGMAX and EIGMIN.

IOp(1/22)

L107: Whether to reorder coordinates for maximum coincidence.
0                Yes.
1                Assume reactant order equals product order.
2                Read in a re-ordering vector from the input.

L115/L123: Kind of search.
0                Both directions and generate search vector.
1                Forward direction and generate s. vector.
2                Backward direction and generate s. vector.
3                Both directions and generate s. vector.
4                Forward direction and read s. vector 8F10.6.
5                Forward direction and read s. vector 8F10.6.
6                Backward direction and read s. vector 8F10.6.
7                Both directions and read s. vector 8F10.6.

IOp(1/23)

L112: Derivative availability.
0                Energy only.
1                Energy + Forces.
2                Energy + Forces + Force constants.

IOp(1/24)

Whether to round tetrahedral angles.
0                Default (Yes).
1                Yes, round angles within 0.001 degree.
2                No.

IOp(1/25)

Whether SCRF is used with numerical polarizability.
0                No.
1               Yes, the field in /Gen/ must be cleared each time.

IOp(1/26)

Accuracy of function being optimized: -NNMM Energy 10-(NN), Gradient 10-(MM).
-1              Read in values.
0                Default (same as 1).
1                Normal accuracy for HF (energy and gradient both 1.d-7).
2                Standard grid accuracy for DFT (Energy 1.d-5, gradient 1.d-4).
3                Fine grid accuracy for DFT (Energy 1.d-7, gradient 1.d-6).

IOp(1/27)

= IJKL (i.e. 1000*I+100*J+10*K+L):
Transition state searching using QST and redundant internal coordinates
L= 0,1       Input one structure, either initial guess of the minimizing structure or transition structure without QST.
L= 2          Input 2 structures. The first one is the reactant, the second one is the product. The union of the two redundant coordinates                   is taken as the redundant coordinates for the TS. The values of the TS coordinate are estimated by interpolating the                            structure of R and P. R and P are used to guide the QST optimization of the TS.
L= 3          Input 3 structures. The first one is the reactant the second one is the product. The third one is the initial guess of the                   transition structure. R and P are used to guide the QST optimization of the TS.
K = 1-9     Interpolation of initial guess of TS between R and P (TS=0.1*J*R + 0.1*(10-J)*P, default J=5).
J = 1          LST constraint in internals.
J = 2          QST constraint in internals.
J = 3          LST constraint in distance matrix space.
J = 4          QST constraint in distance matrix space.
I = 0-9       Control parameters for climbing phase of QST (e.g. QSTRad = 0.01*I, default QSTrad = 0.05).

IOp(1/28)

L103: Number of translations and rotations to remove during redundant coordinate transformations.
-2              0.
-1              Normal (6 or 5 for linear molecules).
0               Default, same as -1.
N              N.

IOp(1/29)

L101: Specification of nuclear centers.
0               By z-matrix.
1               By direct coordinate input (must set IOp(29) in L202).
2               Get z-matrix and variables from the checkpoint file.
3               Get Cartesian coordinates only from the checkpoint file.
4               By model builder, model A.
5               By model builder, model B.
6               Get z-matrix from the checkpoint file, but read new values for some variables from the input stream.
7               Get all input (title, charge and multiplicity, structure) from the checkpoint file.
10             Print details of the model building process.
000           Default (same as 100).
100           Do not abort job if model builder generates a z-matrix with too many variables.
200           Abort job if model builder generates a z-matrix with too many variables.
1000         Read optimization flags in format 50L1 after the z-matrix.
2000         Set all optimization flags to optimize.
3000         Purge flags except the frozen variables.
4000         Rebuild the coordinate system.
5000         (2+3) Purge all flags but keep the coordinate definition.
6000         Generate new redundant coordinates, reading an input section selecting frozen and optimized atoms.
00000       Default, same as 10000.
10000       Mark z-matrix constants as frozen variables rather than wired-in constants.
20000       Do not retain symbolic constants.
100000     Generate a symbolic z-matrix using all Cartesians if none is present on the checkpoint file (a hack to make IRCs work with                  Cartesian input).
200000     Same as 1, but retain the redundant internal coordinate definitions.
0000000   This is the default. Read from the input stream in the format implied by the ones digit (cartesian coordinates, z-matrix, etc.)
1000000   Get input type or chk file name to read from input stream; title and charge/multiplicity for each structure read from input.
2000000   Read input type for each structure from input stream; title and charge/multiplicity are those of last chk file read.
9000000   Same as 0000000.

IOp(1/30)

L103: Are the read-write files to be updated? This option is set for the last call to 103 in frequency calculations in order to preserve the values of the variables for archiving. It also suppresses error termination on large gradients.
0               Yes.
1               No, print internal coordinate step but don't set up for microiterations and don't update the RWF.
2               Set up for step but don't update coordinates; for QM/MM iterative frequencies.

IOp(1/32)

Title card punch control.
0               Don’t punch.
1               Punch.

IOp(1/33)

L101, L102, L103, L106, L109, L110, L113, L114: Debug print.
0               Off.
1               On.

IOp(1/34)

L101, L102, L103: Debug + Dump print.
0               Off.
1               On.

IOp(1/35)

L102-L112: Restart.
0               Normal optimization.
1               First point of a restart. Get geometry, wavefunction, etc. from the checkpoint file.

IOp(1/36)

Checkpoint.
0               Normal checkpoint of optimization.
1               Suppress checkpointing.

IOp(1/38)

Entry control option (currently only by L103, L106, L107, L108, L109, L110, L111, and L112 but not L102 or L105).
0               Continuation of run.
1               Initial entry.
N>1          In L103: Initial entry of guided optimization using N levels.
N0            In L106: differentiate Nth derivatives once. In L110 and L111: differentiate energy N times.
000           In L106: differentiate with respect to nuclear coordinates.
100           In L106: differentiate with respect to electric field.
200           In L106: differentiate with respect to field and nuclear.
1000         In L106: Save original forces and force constants.
00000       In L106: Assume all quantities available at the central point will also be computed at displaced points.
10000       In L106: No analytic nuclear coordinate derivatives will be done at displaced points, even though they were done at the                  central point.
000000     L106 control of number of diff. steps.
100000     Do 2-point differentiation (one step each way).
200000     Do 4-point differentiation (two steps each way).
0000000   Default (1).
1000000   Differentiate with respect to translation vectors for PBC for elasticity.
2000000   Do not differentiate with respect to translation vectors.

IOp(1/39)

L106, L109, L110, L111: Step size control for numerical differentiation.
L115: Path step size.
0               Use internal default (0.001 Angstroms and 0.001/3 au E-field in L106, 0.005 Å in L109, 0.01 Angstrom in L110, 0.001 au                  in L111).
N              Use step-size of 0.0001*N (angstroms in L106, L109, L110, electric field au in L111). In L106, the electric field step will                  be 3x smaller.
-1              Read step size (up to 2 for L106, 1 for others), free-format.
-N>1         Use step-size of 0.0001*N atomic units everywhere.

L123: Step-size.
0               Default (0.1 Bohr, except 0.075 bohr for EulerPC, or original value if restart. DVV default is 0.25 fs).
N<0          Supplied step size is in units of sqrt(amu)*Bohr.
N>0          Supplied step size is in units of Bohr.

IOp(1/40)

L113, L114: Hessian recalculation.
-1              Pick up analytic second derivatives every time.
0               Just update. The default, except for CalcAll.
N              Recalculate the Hessian every N steps.

L116: Whether to read initial E-field.
0               Start with 0.0.
1               Read from checkpoint file.
2               Read from input stream.

L123: Truncation error threshold for the modified BS integration routine (EPS).
0               Default (10-8 Bohr).
N              10-N Bohr.

IOp(1/41)

Step number of optimization from which to take geometry.
-1              The initial geometry.

IOp(1/42)

L103, L115, L123: Number of points along the reaction path in each direction.
0               Default is 10.

L117: Cutoff to be used in evaluating densities.
0               1.0D-10.
N              1.0D-N.

IOp(1/43)

L116: Extent of Reaction Field.
0               Dipole.
1               Quadrupole.
2               Octapole.
3               Hexadecapole.

L117: How to define Radii
0               Default is 11.
1               Use internally stored Radii, centers will be on atoms.
2               Read-in centers and radii on cards.
10             Force Merz-Kollman radii (Default).
20             Force CHELP (Francl) recommended radii.
30             Force CHELPG (Breneman) recommended radii.
100           Read in replacement radii for selected atom types as pairs (IAn,Rad) or (Symbol,Rad), terminated by a blank line.
200           Read in replacement radii for selected atoms as pairs (I,Rad), terminated by a blank line. Initial radius of spheres to be                  placed around attractors to "capture" the gradient trajectories. The final radius is then automatically optimized separately for                  each atom.

IOp(1/44)

L115 and L123: IRC Type.
0               Default (same as 3).
1               Cartesian.
2               Internal (L115 only).
3               Mass-weighted.

L117: Maximum distance between a nucleus and its portion of the isosurface - used in Trudge only to eliminate, from the outset, points which clearly lie in another basin. This parameter should be chosen with the parameter Cont in mind.
0               10.0 au.
NM           N.M au = NM/10.

L121: Seed for random number generator (ISeed).
-1              Use system time initialize iseed (Note each run will give different results).
0               Use default seed value (ISeed = 398465).
N              Set random number seed to N.

IOp(1/45)

L123: Options.
00             Which IRC Integrator to Use. Default=3, except 6 for ONIOM QuadMac/Micro or 1 for GradientOnly.
01             Euler.
02             LQA.
03             HPC.
04             GS2.
05             DVV.
06             Euler-based PC.
10             Coordinate driving schemes.
0xx           Is the integration being done on an empirical surface? Default=2.
1xx           Yes, this is an empirical surface. The energies and derivatives required for the IRC integration are NOT evaluated in this                  link. Instead it is assumed that an external program communicates the appropriate values with Link 402, etc. Also, the force                  constant matrix, when needed, is simply diagonalized, i.e. translation and rotation projections are NOT used. Also, all                  atomic masses are set to 1.
2xx           No.
0xxx         Order of magnitude for the step size relative to the integer value given with the StepSize=N option on the route line --                  IOp(1/39). Default=2.
Nxxx         Integration step size is taken as IOp(1/39)*10-N.
0xxxx        Whether or not energies reported in the final summary table should be given relative to the TS energy. Default=1.
1xxxx        Yes.
2xxxx        No.
0xxxxx      Whether or not statistics over coordinates should be converted to Angstoms/Degrees when reported in the summary table.                  Default=1.
1xxxxx      Yes.
2xxxxx       No.
0xxxxxx     Should a URVA input file be written? Default=2.
1xxxxxx     Yes.
2xxxxxx     No.

IOp(1/46)

Order of multipoles in numerical SCRF.
0               Dipole.
1               Quadrupole.
2               Octapole.
3               Hexadecapole.

IOp(1/47)

Number of redundant internal coordinates to allow for.
0               Default: Max(50000,MDV/(100*NStruc)).
N              N.

IOp(1/48)

IRCMax control.
1               Do IRCMax.
20             Include zero-point energy.

IOp(1/49)

Options to IRC path relaxation (IJKL).
L               2/1 (don’t/do optimize reactant structure). Default: 1.
K              2/1 (don’t/do optimize product structure). Default: 1.
J               3/2/1 (don’t/QST3/QST2 optimize TS structure (for QST input)). Default: 1.
I                2/1 (unimolecular/bimolecular reaction). Default: unimolecular.

IOp(1/52)

L101 and L120: Type of ONIOM calculation.
0/1            One layer, normal calculation.
2               Two layers.
3               Three layers.
00             Default (20).
10             Include electrostatics in model systems using MM charges (in case of three-layer ONIOM, this includes the charges in both                  the small model and the intermediate model system).
20             No electrostatics included in the model systems.
30             As 10, but exclude the MM charges in the calculations on the smallest model system in case of a three-layer calculation.
40             As 10, but exclude the MM charges in the calculations on the intermediate model system in case of a three-layer calculation.
100           Do full square for testing.
N000        Use atomic charge type N-1 during microiterations. The default is MK charges.
M0000      Type of link atoms for the MM calculation in QM/MM.
                 0          Default (2).
                 1          Conventional (Maseras) style.
                 2          ONIOM style.
L00000    Whether to read additional charges with electronic embedding.
                 0          Default (1).
                 1          No.
                 2          Yes.
K000000  Whether to create new entries in Common/Mol for the link atoms.
                 0          No.
                 1          Yes.

IOp(1/53)

L120: Action of each invocation of L120.
0               Do nothing.
1               Set up point MM on RWF from initial data.
2               Set up point MM on RWF from initial data and restore point MM on checkpoint file if ONIOM data is present there.
3               Restore point M from data on the RWF.
4               Integrate energy.
5               Integrate energy and gradient.
6               Integrate energy, gradient, and Hessian.
7               Restore point MM from RWF but do not create a new model system.
NN0         Save necessary information (some RWF's, energy, gradients, Hessian) of point NN of the ONIOM grid. NN =                  MaxLev2 + 1 (currently 17) to restore real system.
MM000    Next point to do is MM.

Calc Level
High          4--7--9
                 |     |     |
Mid           2--5--8
                 |     |     |
Low          1--3--6
                 S   M   L       system size

IOp(1/54)

Whether to recover initial energy during IRCMax from checkpoint file.
0               No.
1               Yes.

IOp(1/55)

L103: Options for GDIIS: ICos*1000+IChkC*100+IMix*10+Method form.
L115: IRC optimization.
0               Default, use gradients to find the next geometry.
1               Use displacements to find the next geometry.

IOp(1/56)

Set of atom type names to parse.
0               Accept any.
1               Dreiding/UFF.
2               Amber.
3               Amber allowing any symbol, for use with parameters in input stream.

IOp(1/57)

Whether to produce connectivity.
0               Default (4 if reading geometry from checkpoint file and connectivity is there, otherwise 3).
1               No.
2               Yes, read from input stream.
3               Yes, generate connectivity.
4               Yes, read from checkpoint file.
5               Yes, read from RWF file.
10             Read modifications.
100           Connectivity input is in terms of z-matrix entries, including dummy atoms.

IOp(1/58)

L115: IRCMax control.
1               Do IRC rather than IRCMax.
10             Store compound energy; default for IRCMax.
20             Zero-point energies are available during IRCMax.

IOp(1/59)

L103: Update of coordinates.
0               Default (1).
1               New versions.
2               Old version.
00             Default (10).
10             Re-use eigenvectors of G only if exact.
20             Re-use eigenvectors of G if they are linearly independent.
30             Test old eigenvectors of G but don't re-use them.
40             Don't look at old eigenvectors.

IOp(1/60)

Interpret extra integer and fp values in z-matrix as scan information.
0               Default (No).
1               Yes.
2               No.

IOp(1/61)

How ONIOM should leave the RWF at the end of each geometry.
0               Default (1).
1               Normal: leave the RWF set up for the low-level calculation on the real system.
2               MOMM: leave the RWF set up for the real system, but with NBasis and NBsUse for the high-level calculation on the                  model system. Useful for treating the full system as having electrons only on the QM atoms.

IOp(1/62)

Counterpoise control.
NN          NN fragments, NN < 50.
1NN        Force use of new ghost atoms (default).
2NN        Force use of old ghost atoms.
1xxx         Counterpoise (default).
2xxx         Fragment guess.

IOp(1/63)

Step in counterpoise calculation.
MNN        M = order of derivatives (1=Energy, 2=Gradient, ...)
                 NN = 0                                  Supermolecule
                        = 1-NFrag                       Fragments with ghost atoms
                        = NFrag+1 - 2*NFrag     Lone fragments

IOp(1/64)

Molecular mechanics force field selection.
0               None.
1               Dreiding.
2               UFF.
3               AMBER.
000           Use only hard-wired.
100           Use soft and hard-wired, hard-wired has priority.
200           Use soft and hard-wired, soft has priority.
300           Use only soft. Lowest 2 digits then have no meaning.
0000         Do not read modifications to parameter set.
1000         Read modifications to parameter set.
00000       With soft parameters, abort when different parameters match to the same degree.
10000       Use the first when there are equivalent matches.
20000       Use the last when there are equivalent matches.

If IOp(67)=3, then the default is to apply soft parameters with higher priority.

IOp(1/65)

Control of which terms are included in MM, corresponding to the 'classes' in FncInf.
0               Do all (default).
1               Non-bonded.
10             Stretching.
100           Bending.
1000         Torsion.
10000       Out-of-plane.
100000     Stretch-bend.

IOp(1/66)

Whether to generate QEQ charges, over-write the values in AtChMM, or to use the values already there.
0               Default (2, 1==> 221).
1               Do QEq.
2               Don't do QEq.
00             Default (20).
10             Do for atoms which were not explicitly typed.
20             Do for all atoms regardless of typing.
000           Default (200).
100           Do for atoms which have charge specified or defaulted to 0.
200           Do for all atoms regardless of initial charge.

IOp(1/67)

Source of MM parameters.
0               Default: 2 if reading geometry from checkpoint file, else 1.
1               Generate here, reading from input if requested by IOp(64).
2               Copy from checkpoint file.
3               Pick up non-standard parameters from checkpoint file.

IOp(1/70)

L118: Type of sampling (Nact).
0               Default (same as 3).
2               Classical microcanonical normal mode sampling.
3               Fixed normal mode energy.
4               Local mode sampling (thermal sampling based on RTemp).
10             Read in Hessian from checkpoint for initial sampling.

IOp(1/71)

L115: Whether to print out input files for each structure along an IRC.
0               No.
1               Yes.

L118: Hessian update.
-1             Gradient only.
-2             Gradient+Hessian, but never calculate full H (only updates).
0               Full Hessian at every step.
NN           Try to do NN updates between full Hessians.
000           Default updating (same as 300).
100           SR1 Hessian updating algorithm.
200           PSB Hessian updating algorithm.
300           Bofill's Hessian updating algorithm.
400           Sqrt(Bofill) Hessian updating algorithm.
500           No update.
0000         Default (same as 1000).
1000         Reintegrated updated steps.
2000         Suppress reintegration.

L123: Hessian calculation.
-1             Gradient only.
0               Either only update or CalcAll as determined by IOp(10).
N              Recalculate analytic Hessian every Nth calculation.

IOp(1/72)

L121: Lagrangian constrain method for ADMP (ICType).
Half*Gamma*Tr[(P*P-P)2] + Lambda*[Tr(P)-Ne] + Eta*Tr(P*P-P)
0               Default same as 7 if no mass-weighting (IOp(76) < 0). Same as 10 if mass-weighting (IOp(76) > 0).
1               Use Lambda and Eta only. (Gamma=0).
2               Use Lambda, Eta, Gamma. Gamma = .2.
3               Use Lambda, Eta, Gamma. Gamma = 1. Constraints for scalar mass case.
4               Use exact constraint Sum(ij)[Vij*(P2-P)ij].
5-7            Iterative Scheme same as 4. Different initial guesses. 7 is default for scalar mass case. Constraints for tensorial mass.
8-11          Mass-weighting constraints. Documentation may be found in DVelV1. 10 is default.

L124: Solvent type for external iteration PCM. (ISolv).

IOp(1/73)

L123: Whether to compute projected frequencies: 0/1/2   Default (No)/No/Yes.

L118 and L121: Initial Kinetic energy of the Nuclei (EStrtC).
0               Default (.1 Hartree).
N>0          N*micro-Hartree.
N<0          0.0 Hartree

IOp(1/74)

Charge scaling for charge embedding in ONIOM. IJKLMN 6th through 1st nearest neighbors of current layer scaled by I*0.2, J*0.2, etc. 0 ==> 5 => IAtTyp=6 (no scaling); all layers are scaled by at least as much as ones farther out. The default is 500.
M              Factor for charges one bond away from link atom.
L0             Factor for charges two bonds away from link atom.
K00          Factor for charges three bonds away from link atom. IJ etc.
                 The actual factors used for each value of IAtTyp are:
                 1: 0.0
                 2: 0.2
                 3: 0.4
                 4: 0.6
                 5: 0.8
                 6: 1.0

IOp(1/75)

ADMP control flag (ICntrl)
0               Standard ADMP.
1               Read converged density at every step.
2               Fix the nuclear coordinates.
3               Test time reversibility (MaxStp must be even).
00             Default (20).
10             Read stopping parameters from input.
20             Do not read stopping parameters.

IOp(1/76)

+/- XXXXZYYYY Fictitious electron mass (EMass)
YYYY      Default (1000)
                 IOp(1/76)>0 YYYY*.0001 AMU. MW core functions more than valence functions.
                 IOp(1/76)<0 YYYY*.0001 AMU. Use uniform scaling for all basis functions.
                 (Note YYYY > 9999 makes no sense).
Z               Mass-weighting option. If IOp(76)<0, Z is meaningless.
XXXX      If PBC: Mass of Box Coordinates (BoxMas) = XXXX*.0001 AMU BoxMas=0
                 Box coordinates not propagated (default).

IOp(1/77)

Initial Kinetic energy of the density matrix (EStrtP) (For UHF, Alpha and Beta each get half this energy) and Option Number to compute initial kinetic energy. Format of Input: XXYYYY (six digits).
IWType = XX
N = YYYY
(For UHF, Alpha and Beta each get half this energy).
0               Default (0.0 Hartree).
N>0          N*micro-Hartree IWType is used to figure out how the initial velocity is computed (in gnvelp).
                 If XXYYYY < 0: Initial velocity = 0.0 Hartree (i.e., currently same as N=0 above).

IOp(1/78)

L121: Sparse.
-N             Sparse here with cutoff 10(-N), full elsewhere.
0               Use full matrices or sparse based on standard settings.
1               Use sparse fixed form.

IOp(1/79)

L115: IRCMax convergence.
L118, L121: stopping criteria.
0               Default, do not analyze pure rotation and vibration for polyatomic molecules.
1               Do pure rotational and harmonic normal mode analysis for polyatomic molecule; EBK theory for diatomic vibrational                  analysis (require equilibrium information for each of the polyatomic molecules from saved checkpoint files and Morse                  parameters for diatomic molecule).
2               Do pure rotational and harmonic normal mode analysis for polyatomic molecule; local harmonic vibrational analysis for                  diatomic molecule (require equilibrium information for each of the fragments from saved checkpoint files).
3               Do pure rotational analysis and select the best normal mode analysis methods (harmonic and anharmonic) for polyatomic                  molecule; local harmonic vibrational analysis for diatomic molecule (require equilibrium information for each of the fragments                  from saved checkpoint files).
00             Default, use default stopping criteria.
10             Use user specified stopping criteria.

IOp(1/80)

L106: 0/1 Cartesian/Normal mode.

L118: =1 to suppress the 5th order correction after surface hop has been made in Trajectory Surface Hopping calculations. Needs also IOp(10/80=1).

L121: Nuclear Kinetic Energy Thermostat Option.
0                  No Thermostat.
11XXXXX  Velocity scaling, but only for the first XXXXX simulation steps. (This option is useful, if thermostating is only required                     during equilibration.)
1000000      Velocity scaling, all the way through the simulation.

IOp(1/81)

Nuclear KE thermostat in ADMP -- temperature is checked and scaled every IOp(81) steps.

IOp(1/82)

L121: Temperature for nuclear KE thermostat.

IOp(1/83)

Whether to read in frequencies for electric and magnetic perturbations.
0               Default (No).
1               Yes.
2               No.
00             Default (10).
10             Ensure that the static case is done, by putting a zero frequency at the beginning.
20             Do not put a zero frequency at the beginning.

IOp(1/84)

Differentiation of frequency-dependent properties.
0               No.
N              Mask for which properties on file 721 will be differentiated.

IOp(1/85)

Band gap calculation in PBC ADMP.
0               Default (No).
1               Diagonalize Fock matrix to get band gap, evolution, etc.
2               No.

IOp(1/86)

Printing for NMR for ONIOM.
0               Default (1).
1               Print tensors and eigenvalues.
2               Print eigenvectors as well.

IOp(1/87)

ONIOM integration of density.
0               Do not integrate.
1               Integrate current densities.
2               Integrate densities specified by following digits:
K0            Density to use from gridpoint 1
L00           Density to use from gridpoint 2
M000        etc.
Values for K, L, M, etc.:
                 0: SCF
                 1: MP first order
                 2: MP2
                 3: MP3
                 4: MP4
                 5: CI one-particle
                 6: CI
                 7: QCI/CC
                 8: Correct to second order

IOp(1/88)

Whether to read in atomic masses (isotopes).
0               Default (1 if geometry read from input, 4 if geometry read from checkpoint)
1               Use most abundant isotopes.
2               Read isotopes from input. The temperature and pressure are read first, for backwards compatibility.
3               Read isotopes from RWF.
4               Read isotopes from checkpoint.
5               Isotopes were read from chk file during Guess=Input (generated internally).

IOp(1/89)

Maximum allowed deviation from average nuclear KE during ADMP, in Kelvin.

IOp(1/90)

To read in the velocity in Cartesian coordinates.

IOp(1/91)

Nuclear Kinetic Energy Thermostat Option. Average energy (in micro-Hartree) to be maintained during simulation, as required by IOp(80).

IOp(1/92)

Thermostat Option. Maximum allowed deviation from average nuclear KE specified in IOp(81). Also in micro-Hartree.

IOp(1/93)

QM/MM TS vector guess.
1               Retrieve from checkpoint file if available, otherwise diagonalize QM Hessian or read from input (default).
2               Do not try to retrieve from checkpoint file.
10             Diagonalize QM contribution to Hessian (default).
20             Read from input.
N00          How to deal with 'suspicious RFO solutions' (default is 1).
                 1. Just take the step.
                 2. Check if there is an eigenvector with wrong curvature. If there is, flip its eigenvalue.
                 3. Check if there is an eigenvector with wrong curvature. If there is, take a small step into this direction, followed by a linear                  search. This should step out (or stay in) the wrong region, and fix the eigenvalue.

IOp(1/94)

Davidson control for quadratic micro-iterations.
OP             Number of initial guess vectors (4).
MN00        Iteration to scale down number of vectors (5).
KL0000     Factor to scale down with; 1 for no scaling (2).
J000000    Whether to do geometry steps when the CG is done (2).
                 1          Make the CG steps.
                 2          No displacements.
                 3          Only do displacements at first guess.
I0000000  Whether to re-use previous RFO solution or to regenerate guess (1).
                 1          After first step, use previous solution as guess.
                 2          Regenerate guess each time.
                 3          Use previous lowest root, and regenerate remainder.
H00000000  Whether (1, default) or not (2) to add 0,..,0,1 guess vector.

IOp(1/95)

RFO/Davidson control for quadratic micro-iterations.
MM          Convergence (7).
LLL00      <0:        Regular Davidson.
                 0:          Only check convergence on first vector, and iterate the lowest root only. Use all the intermediate vectors.
                 >0:        Only check convergence on first vector, and iterate the new vectors LLL times with the explicit last row/column.                  This is specifically appropriate for RFO. The last row/column of the Hessian comes after the diagonal elements.

IOp(1/96)

Davidson control for coupled QM/MM macro step. See IOp(94).

IOp(1/97)

RFO/Davidson control for coupled QM/MM macro step. See IOp(95).

IOp(1/98)

Control of quadratic micro-iterations and coupled QM/MM quadratic macro step.
<0             Do not use dynamic convergence criteria for the micro-iterations.
0               Default (11).
1               Regular non-coupled macro step.
2               Coupled macro step, full diagonalization.
3               Coupled macro step, direct /w full Hessian in core.
4               Coupled macro step, direct /w MM Hessian in core.
5               Coupled macro step, fully direct.
6               Go through the QuadMac machinery, but use the fully integrated ONIOM Hessian to calculate the Hessian-vector                  products. Switch to regular micro-iterations at points without analytic second derivatives.
7               Fully quadratic at 2nd derivative points (1st in CalcFC, all in CalcAll), QuadMac with integrated Hessian at non-2nd                  derivative points.
10             Regular micro-iterations.
20             Quadratic micro-iterations, full diagonalization.
30             Quadratic micro-iterations, direct with prepared Hessian in core.
40             Quadratic micro-iterations, direct with raw MM Hessian in core.
50             Quadratic micro-iterations, fully direct.
60             No micro-iterations.

IOp(1/99)

Accuracy used for the non-bonded interactions in the Hessian-vector product calculations in the fully direct algorithms. Setting this IOp does not affect the MM energy and gradient calculations; only the direct evaluation in the QuadMac optimization step. When IOp(99)<0, the full accuracy is used.
MM              Maximum multipole level (8)
LLL00          Box size in FMM (12)
KKK00000  Cutoff in van der Waals (30)

IOp(1/101-104)

Phase control in L115 and L118: N1, N2, N3, N4.

IOp(1/105)

Reaction direction.
00             Default (Same as 10).
10             Forward direction.
20             Reverse direction
Damped-Velocity Verlet (DVV) options for Dynamic Reaction Path following.
0               Default (Same as 2).
1               Use DVV.
2               Do not use DVV.
00             Default (Same as 10).
10             Follow the rxn path in the forward direction
20             Follow the rxn path in the reverse direction.
000           Default (Same as 200).
100           Time step correction not used.
200           Time step correction used but not to recalculate current DVV step.
300           Time step correction used and current DVV step recalculated.
0000         Default (Same as 1000).
1000         Use DVV stopping criteria.
2000         Do NOT use DVV stopping criteria

IOp(1/106)

Damping constant for DVV Dynamic Reaction Path following (v0).
0                Default v0=0.04 (N=400).
N               v0 is set to N*0.0001.

IOp(1/107)

Error tolerance for DVV time step correction (Error).
0               Default Error=0.003 (N=30).
N              Error=N*0.0001.

IOp(1/108)

Gradient magnitude for DVV stopping criteria (Crit1).
0               Default (N=15).
N              N*0.0001

IOp(1/109)

Force-velocity angle for DVV stopping criteria (Crit2).
0               Default (90 Degrees).
N              Use N Degrees.

IOp(1/110)

Scaling of rigid fragment steps during microiterations.
0               Do not scale.
1               Scale with 1/NRA (NRA = number of atoms in fragment).
2               Scale with 1/Sqrt(NRA).
-n              Scale with 1/n.

IOp(1/111)

Step-size to use with steepest descent when L103 is having trouble.
-N             Scale up to RMS step of N/1000 if DXRMS is less.
-1              Effectively disables the scaling.
0               Default (50).
N              Scale up or down to maximum change in a variable of N/1000.

IOp(1/112)

Temperature for thermochemistry.
0               Default (standard temperature, unless read in).
N              N/1000 degrees.
-N            N/1000000 degrees.

IOp(1/113)

Pressure for thermochemistry.
0               Default (1 atmosphere, unless read in).
N              N/1000 atmospheres.
-N            N/1000000 atmospheres.

IOp(1/114)

Scale factor for harmonic frequencies for use in thermochemistry and harmonic vibration-rotation analysis.
0               Default (1 unless specified by IOp in overlay 7 or read in).
N              N/1000000.

IOp(1/115)

Compression for MOMM quadratic steps.
4               Second derivatives generated over active atoms, with real system terms done iteratively during micro-iterations.
N≠4        Full second derivative matrices are used.

IOp(1/116)

Options for ONIOM Conical intersections: which calculations have adiabatic couplings done.
0               Default (111: all component calculations).

IOp(1/118)

Dump structures for each ONIOM system formatted as input.
0               Default (No).
1               Yes.

IOp(1/119)

Control Initial Lanczos Vector (ILzVec).
-1              Read guess by card in input file.
-2              Use the largest elements of H as a guess.
-3              Use the five largest contributions of H as a guess.
0x              For Opt, IRC, dynamics read guess from previous cycle.
1x              For Opt, IRC, dynamics generate a fresh guess for each cycle

IOp(1/120)

Flags for QM:QM embedding. NOTE: The standard embedding flags must also be set in the same way as necessary for QM:MM embedding calculations.
0               Default - Same as 1.
1               Use Mulliken charges.
-1              Use the nuclear charge stored in array AtmChg.
-2              Set the charges to zero.
00              Default (Same as 20).
10              Just use the charges that already reside in AtChMM.
20              Update AtChMM using current atomic charges on the RWF.
This option is only employed immediately following low-level real-system sub-calculations.

IOp(1/121)

L106: Extra items to differentiate.
0               Default, none.
1               Differentiate AO density and Fock matrices.

IOp(1/122)

Read secondary structure information.
0               Default (4 or 3 if reading geometry from checkpoint or RWF file, otherwise 2).
1               No.
2               Yes, read from input stream if any residue information was provided on the atom definition lines.
3               Yes, read from RWF.
4               Yes, read from checkpoint.

IOp(1/123)

Version of /Mol/ to save on disk.
0               Default (current, version 2).
1               Version 1 (flag -12345).
2               Version 2 (flag -12346).
N<0          Flag value N.

IOp(1/124)

Flavor of ONIOM-PCM to use.
1               "A", reaction field from the ONIOM integrated density;
2               "B", reaction field from the real system low level;
3               "C", reaction field in the real system low level only;
4               "X", reaction field in all subcalculations using the real system cavity.

IOp(1/125)

Solvent charge distribution to add to Hamiltonian.
0               None.
1               Read charges and DBFs from input stream in input orientation.
2               Read from RWF.
3               Read from checkpoint file.
4               Same as 1.
5               Read charges and DBFs from input stream in standard orientation.
10             Force units of Angstroms for coordinates.
20             Force units of Bohr for coordinates.

IOp(1/126)

Whether to read an input section with atom opt/freeze information.
0               Default (2).
1               Yes.
2               No.

IOp(1/128)

Initial micro-iterations in L120 before first QM step, and micro-iterations in L120 during numerical differentiation in L103.
0               Default (No).
1               Yes.
2               No.

IOp(1/129)

L123: Whether or not the final statistics printed in the job summary should include coordinate values at each IRC step.
0               Default (none).
1               Read user-defined stats from the input file.
0x             Default (do not report all Cartesian coordinates).
1x             Report all Cartesian coordinates.
0xx           Unused.
0xxx          Default (do not report bond coordinates).
1xxx          If redundant internals are on the RWF, then report values for bond coordinates along the IRC.
0xxxx        Default (do not report angle coordinates).
1xxxx        If redundant internals are on the RWF, then report values for angle coordinates along the IRC.
0xxxxx      Default (do not report dihedral coordinates).
1xxxxx      If redundant internals are on the RWF, then report values for dihedral coordinates along the IRC.

IOp(1/130)

Eigenvector number to be followed during coordinate driving jobs [IOp(1/19=10)].
0               Default (1).
N              Follow input structure Hessian eigenvector number N.

IOp(1/131)

Options for corrector integration in predictor-corrector IRC calculations (Link 123).
-01           After each corrector integration, evaluate the actual energy and derivatives, but do not actually use these. The final IRC will                 be the same as 1.
00            Should the corrector integration scheme be run in an (macro-cycle) iterative fashion? Default=2.
01            Never check convergence of the corrector integration. Always do one corrector integration for each predictor integration.
02            Always check for convergence of the corrector integration end point. Convergence is achieved when the change in corrector                 integration end point geometry is less than the convergence criteria indicated by IOp(7).
03            Same as 2, but never accept convergence after the first corrector integration at a point.
10            This particular flag iteratively refines the DWI fitted surface if multiple corrector integration macro-cycles are taken by adding                 the largest standard deviation point from the previous BS cycle.
11            This flag forces a PES evaluation step after each corrector integration. This is similar to option -1, except that the actual                 energy and derivatives are used for the next predictor step rather than the values on the DWI fitted surface at the corrector
                end-point.
0xx          Should DWI surfaces employ numerical third-order terms in Taylor series? Default=1.
1xx          Use DWI surface with Taylor series expansions truncated at second-order.
2xx          Use DWI surface with Taylor series expansions truncated at third-order using numerical third-derivatives.
Nxxx       Power to be used for DWI weights that include a power of delta-x. This option uses (delta-x)2N. The default is                 N=1.                
0xxxx       How should the first step off of the transition structure point be handled in corrector integration cycles? Note, in all cases, the                 transition vector is used to define the tangent at the transition structure. Default=2.
1xxxx       Run the requested number of Euler steps in the standard way. Only the first Euler step taken uses the transition vector.
2xxxx       Take a large step off of the transition structure point along the transition vector. This step is taken to be half of the total                 requested step size given by TotStp.
3xxxx       This the same as option 2 in concept. The only difference is that the first step off of the transition structure is taken as                 one-third the total requested step size given by TotStp.
4xxxx       This the same as option 2 in concept. The only difference is that the first step off of the transition structure is taken as                 one- fourth the total requested step size given by TotStp.
0xxxxx     Should update vectors be used in DWI fits if possible? Default=1.
1xxxxx     Yes, when possible.
2xxxxx     Never.

IOp(132)

Whether to check for divalent link atoms in ONIOM input:
0               Default (yes).
1               Yes.
2               No.

IOp(135)

MM Non-bonded switching function.

IOp(136)

MM van der Waals outer cutoff in Angstroms.

IOp(137)

MM Coulomb outer cutoff in Angstroms.

IOp(138)

MM soft cutoff range (applied to both van der Waals and Coulomb), in Angstroms.

IOp(139)

Number of MM microiterations allowed.
0               Default, based on NAtoms but at least 5000.
N              N.

IOp(140)

Whether to restore the real system from chk file.
0               Default, yes if ONIOM.
1               Yes.
2               No.

IOp(141)

Control of error choice during GEDIIS:
0               Default (1).
1               Use RFO steps as error vectors, using the NR step at a point if the RFO fails or gives a Hessian eigenvector.
2               If RFO fails for any point, use the gradient for all points.
3               Always use the gradients as the errors.
4               Use RFO steps as error vectors unless any RFO fails and unless Hessian is marked as untrustworthy; then use gradients                  instead.
5               Drop back to RFO (no DIIS) if Hessian is untrustworthy. NR steps are used if RFO fails during DIIS.

IOp(142)

Whether to copy MM charges to link atoms:
0               Default (3 if QEq is done; otherwise 1).
1               Copy if link atom charge is zero.
2               Do not copy.
3               Always copy.

IOp(144)

Whether to analyze residue geometry.
0               Default (Yes, if secondary structure present and NAtoms≤10000)
1               Yes.
2               No.

IOp(146)

Control of SCVS:
0               Default (03045011).
1               Include forces in virial ratio.
2               Do not include forces in virial ratio.
1x             Use Murdoch's extrapolation.
2x             Do not use Murdoch's extrapolation.
Nxx          Apply SCVS when max force on nuclei is below 10(-N).
Mxxx        The convergence on the virial Eta. Default is 5.
Lxxxx        The convergence threshhold on |E| * (2*Eta - 2), where |E| is the magnitude of the kinetic energy is 10(-M). Default is 3.
Kxxxxx     The initial order of extrapolation is 10L.
JJJxxxxxx  Maximum of KKK SCVS iterations.

IOp(151)

How many vectors with negative curvature to use in downhill step during minimization:
0               Default (3).
-1             None, do regular RFO step.
N              Up to N vectors.

IOp(152)

Control of MaxStp (allocated max number of steps in L103):
0               Default: compute based on number of variables, NStep, etc.
N>0          Make MaxStp at least N.
N<0          Make MaxStp at most -N.

IOp(153)

Whether to fill OT file in L103.
0               Default: do so for cartesian and red. int. coord. opts.
1               Yes.
2               No.

IOp(154)

Linear angle test during internal coordinate generation.C
0               Default (15 degrees, applied to all 3 tests).
-N            Threshold N degrees, applied to the angle only.
N              Threshold N degrees, applied to all 3 tests.

IOp(155)

Number of steps to take in guessing a TS during QST2:
0               Default (10).
N              Divide the overall step into N increments.

IOp(156)

Automatic generation of internal coordinates.
0               Default (1).
1               Generate bonds, angles, and dihedrals.
2               Generate bonds and angles but no dihedrals.
3               Generate bonds only.
4               Generate no coordinates automatically.


Last update: 7 November 2011