Role of short-range electrostatics in torsional potentials.
A force field needs to decide if it should contain a torsional potential or not. A helpful guide to this decision should come from a quantum mechanical energy partitioning. Here we analyze the energy profiles of eight simple molecules (ethane, hydrogen peroxide, hydrazine, methanol, acetaldehyde, formamide, acetamide and N-methylacetamide) subject to rotation around a torsion angle. Coulomb interaction energies between all atom pairs in a molecule are monitored during the rotation. Atoms are defined as finite electron density fragments by quantum chemical topology, a method that enables well-defined short-range interactions (1-2, 1-3 and 1-4). Energy profiles of Coulomb interaction energies mostly counteract the ab initio energy profiles. This and future work strives to settle ambiguities in current force field design.
Darley
Michael G
MG
Manchester Interdisciplinary Biocentre, 131 Princess Street, The University of Manchester, Manchester M1 7DN, Great Britain.
Popelier
Paul L A
PL
D000079:Acetaldehyde / Q000737:chemistry; D000081:Acetamides / Q000737:chemistry; D000465:Algorithms; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D004980:Ethane / Q000737:chemistry; D005559:Formamides / Q000737:chemistry; D006834:Hydrazines / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D007700:Kinetics; D000432:Methanol / Q000737:chemistry; D008958:Models, Molecular; D012399:Rotation; D055672:Static Electricity; D013816:Thermodynamics; D054159:Torsion, Mechanical
D000081:Acetamides; D005559:Formamides; D006834:Hydrazines; C029424:hydrazine; C031066:formamide; C030686:acetamide; D006861:Hydrogen Peroxide; D000079:Acetaldehyde; D004980:Ethane; C018595:N-methylacetamide; D000432:Methanol