People
Last update: 30 September 2004

H. Bernhard Schlegel

Contributions to Gaussian:
Optimization methods for both minima and transition states; redundant internal coordinates; trajectory calculations; IRC reaction path following; spin projection; general program development.

• Development and the application of new methods in ab initio molecular orbital (MO) methods, centered around analytical energy derivatives and the use of these derivatives to explore potential energy surfaces
• Applications in a variety of areas including:
• Organic chemistry: reactions involving peroxides, peroxy acids and dioxiranes, reactivity and rearrangements of organic radicals, and the behavior of nitric oxide releasing agents
• Physical chemistry: reactions using embedded cluster methods and studying reaction path branching by ab initio trajectory methods
• Biochemistry: examining the modulation of chemical reactivity by interactions in the active sites of enzymes, for example carboxypeptidase inhibitors and phosphate transferases
• Materials science: Thermochemistry and reactivity of a variety of systems pertaining to silicon CVD (chemical vapor deposition), silane oxidation, Si-H-P, B-H-Cl and titanium-nitride CVD

Rega, N.; Iyengar, S. S.; Voth, G. A.; Schlegel, H. B.; Vreven, T.; Frisch, M. J.; Hybrid Ab Initio / Empirical Molecular Dynamics: Combining the ONIOM Scheme with the Atom-Centered Density Matrix Propagation (ADMP) Approach. J. Phys. Chem. B 108 (2004) 4210-4220.

Anand, S.; Zamari, M. M.; Menkir, G.; Levis, R. J.;Schlegel, H. B.; Fragmentation pathways in a series of CH3COX molecules in the strong field regime. J. Phys. Chem. A 108 (2004) 3162-3165

Knox,J. E.; Hratchian, H. P.; Trease, N.; Struble, J.; Schlegel, H. B.; Holmes, H.; Using Stationary Points on Potential Energy Surfaces to Model Intermolecular Interactions and Retention in GC. Chromatographia 59 (2004) 329-34.

Xia, A.; Knox, J. E.; Heeg, M. J.; Schlegel, H. B.; Winter, C. H.; Synthesis, Structure and Properties of Magnesocene Amine Adducts. Structural Distortions Arising from N-H—C 5 H 5 - Hydrogen Bonding and Molecular Orbital Calculations Thereof. Organometallics 22 (2003) 4060-69.

Schlegel, H. B.; Ab Initio Molecular Dynamics with Born-Oppenheimer and Extended Lagrangian Methods Using Atom Centered basis Functions. Bul. Kor. Chem. Soc. , 24 (2003) 837-842.

Markevitch, A. N; Smith, S. M.; Romanov, D. A.; Schlegel, H. B.; Ivanov, M. Y.; Levis, R. J.; Nonadiabatic Dynamics of Polyatomic Molecules and Ions in Strong Laser Fields. Phys. Rev. A. 68 (2003) 011402(R).

Iyengar, S. S.; Schlegel, H. B.; Voth, G. A.; Atom-centered Density Matrix Propagation (ADMP). Generalizations using Bohmian Mechanics. J. Phys. Chem A. 107 (2003) 7269-77.

Iyengar, S. S.; Schlegel, H. B.; Voth, G. A.; Millam, J. M.; Scuseria, G. E.; Frisch, M. J.; Ab Initio Molecular Dynamics: Propagating the Density Matrix with Gaussian Orbitals. IV. Formal Analysis of the Deviations from Born-Oppenheimer Dynamics. Israeli J. Chem. 42 (2002) 191-202.

Torrent, M.; Vreven, T.; Musaev, D. G.; Morokuma, K.; Farkas, O.; Schlegel, H. B.; Effects of the Protein Environment on the Structure and Energetics of Active Sites of Metalloenzymes. ONIOM Study of Methane Monooxygenase and Ribonucleotide Reductase. J. Am. Chem. Soc. 124 (2002) 192-193.

Endicott, J. F.; Uddin, M. J.; Schlegel, H. B.; Some Spectroscopic Aspects of Electron Transfer in Ruthenium(II) Polypyridyl Complexes. Res. Chem. Intermed. 28 (2002) 761-777.

Rigby, J. H.; Neale, N. A.; Schlegel, H. B.; Mechanistic Studies on Reactions of Bis(alkylthio)carbenes with Vinyl Isocyanates. Heterocycles 58 (2002) 105-113.

Li, X.; Schlegel, H. B.; Photodissociation of glyoxal. Resolution of a paradox. J. Chem. Phys. 114 (2001) 8-10.

Schlegel, H. B.; Millam, J. M.; Iyengar, S. S.; Voth, G. A.; Daniels, A. D.; Scuseria, G. E.; Frisch, M. J.; Ab Initio Molecular Dynamics: Propagating the Density Matrix with Gaussian Orbitals. J. Chem. Phys. 114 (2001) 9758-63.

Yu, Z.; Wittbrodt, J. M.; Xia, A.; Heeg, M. J.; Schlegel, H. B.; Winter, C. H.; Hydrogen and Dihydrogen Bonding as an Important Feature of the Reactivity of the Bridging Hydrogen in Pyrazolate-Bridged Dialuminum Complexes. Organometallics. 20 (2001) 4301-3

Kotra, L. P.; Cross, J. B.; Shimura, Y.; Fridman, R.; Schlegel, H. B.; Mobashery, S. Insight into the Complex and Dynamic Process of Activation of Matrix Metalloproteinases. J. Am. Chem. Soc. 123 (2001) 3108-13.

Halls, M. D.; Schlegel, H. B.; Aroca, R.; Surface-Enhanced Vibrational Spectroscopy. Interpretation of the SERS Spectra of a Chemisorbed Adsorbate on Silver Islands. J. Phys. Chem. A 104 (2000) 9500-05.

Cross, J. B.; Schlegel, H. B.; Molecular Orbital Studies of Titanium Nitride Chemical Vapor Deposition: Gas Phase Complex Formation, Ligand Exchange and Elimination Reactions. Chem. Materials 12 (2000) 2466-74.

McGill, A. D.; Zhang, W.; Wittbrodt, J. M.; Wang, J.; Schlegel, H. B.; Wang, P. G.; Para-substituted N-nitroso-N-oxybenzenamines ammonium salts: A new class of redox-sensitive nitric oxide releasing compounds. Bioorg. Med. Chem. 8 (2000) 405-12.

Schlegel, H. B.; Perspective on "Ab initio calculation of force constants and equilibrium geometries in polyatomic molecules. I. Theory" by P. Pulay [Mol. Phys. 17, 197-204 (1969)]. Theor. Chem. Acc. 103 (2000) 294-96.

Daniels, A. D.; Scuseria, G. E.; Farkas, O.; Schlegel, H. B.; Geometry optimization of kringle 1 of plasminogen using the PM3 semiempirical method. Int. J. Quantum. Chem. 77 (2000) 82-89.

Farkas, O.; Schlegel, H. B.; Methods for optimizing large molecules. II Quadratic Search. J. Chem. Phys. 111 (1999) 10806-14.

Bakken, V.; Millam, J. M.; Schlegel, H. B.; Ab Initio Classical Trajectories on the Born-Oppenheimer Surface: Updating Methods for Hessian-Based Integrators. J. Chem. Phys. 111 (1999) 8773-77.

Wittbrodt, J. M.; Schlegel, H. B.; Structures, Energetics and Transition States of the Silicon-Phosphorus Compounds Si2PHn (n=3D7,5,3,1). An Ab Initio Molecular Orbital Study. J. Phys. Chem. A 103 (1999) 8547-58.

Millam, J. M.; Bakken, V.; Chen, W.; Hase, W. L.; Schlegel, H. B.; Ab Initio Classical Trajectories on the Born-Oppenheimer Surface: Hessian-Based Integrators using Fifth Order Polynomial and Rational =46unction Fits. J. Chem. Phys. 111 (1999) 3800-5.

Bolton, K.; Schlegel, H. B.; Hase, W. L.; Song, K.; An Ab Initio quasi-classical direct dynamics investigation of the F + C2H4 =C6 C2H3F + H Product Energy Distributions. Phys. Chem. Chem. Phys. 1 1 (1999) 999-1011.

Perera, J.; Heeg, M. J.; Schlegel, H. B.; Winter, C. H.; Ruthenium Complexes Bearing h5-Pyrazolato Ligands. J. Am. Chem. Soc. 121 (1999) 4536-37.

Halls, M. D.; Schlegel, H. B.; Comparison of the performance of local, gradient-corrected and hybrid density functional models in predicting infrared intensities. J. Chem. Phys. 109 (1998) 10587-93.

Farkas, O.; Schlegel, H. B.; Methods for optimizing large molecules. I An O(N2) algorithm for solving systems of linear equations for coordinate transformations in quantum chemical geometry optimization. J. Chem. Phys. 109 (1998) 7100-4.

Wittbrodt, J. M.; Hase, W. L.; Schlegel, H. B.; An ab initio study of the interaction of water with cluster models of the aluminum terminated (0001) a-aluminum oxide surface. J. Phys. Chem. B 102 (1998) 6539-48.

Martinez, F. N.; Schlegel, H. B.; Newcomb, M.; Electronic Effects on the Ring Opening of Cyclopropylcarbinyl Radical. J. Org. Chem., 63 (1998) 3618.

Ayala, P. Y.; Schlegel, H. B.; A non-orthogonal CI treatment of symmetry breaking in sigma formyloxyl radical. J. Chem. Phys, 108 7560 (1998).

Ayala, P. Y.; Schlegel, H. B.; Identification and Treatment of Internal Rotation in Normal Mode Vibrational Analysis. J. Chem. Phys., 108 (1998) 2314.

Vreven, T.; Bernardi, F.; Garavelli, M.; Olivucci, M.; Robb, M. A.; Schlegel, H. B.; Ab Initio Photoisomerization Dynamics of a Simple Retinal Chromophore Model. J. Am. Chem. Soc., 119 (1997) 12687.

Shaik, S.; Danovich, D.; Sastry, G. N.; Ayala, P. Y.; Schlegel, H. B.; Dissociative Electron Transfer, Substitution and Borderline Mechanisms of Ketyl Radical Anions. Differences and Difficulties in Their Reaction Paths. J. Am. Chem. Soc., 119 (1997) 9237.