CALCULATION OF MOLECULAR GEOMETRIES, RELATIVE CONFORMATIONAL ENERGIES, DIPOLE-MOMENTS, AND MOLECULAR ELECTROSTATIC POTENTIAL FITTED CHARGESOF SMALL ORGANIC-MOLECULES OF BIOCHEMICAL INTEREST BY DENSITY-FUNCTIONAL THEORY
A. Stamant et al., CALCULATION OF MOLECULAR GEOMETRIES, RELATIVE CONFORMATIONAL ENERGIES, DIPOLE-MOMENTS, AND MOLECULAR ELECTROSTATIC POTENTIAL FITTED CHARGESOF SMALL ORGANIC-MOLECULES OF BIOCHEMICAL INTEREST BY DENSITY-FUNCTIONAL THEORY, Journal of computational chemistry, 16(12), 1995, pp. 1483-1506
Density functional theory is tested on a large ensemble of model compo
unds containing a wide variety of functional groups to understand bett
er its ability to reproduce experimental molecular geometries, relativ
e conformational energies, and dipole moments. We find that gradient-c
orrected density functional methods with triple-zeta plus polarization
basis sets reproduce geometries well. Most bonds tend to be approxima
tely 0.015 Angstrom longer than the experimental results. Bond angles
are very well reproduced and most often fall within a degree of experi
ment. Torsions are, on average, within 4 degrees of the experimental v
alues. For relative conformational energies, comparisons with Hartree-
Fock calculations and correlated conventional ab initio methods indica
te that gradient-corrected density functionals easily surpass the Hart
ree-Fock approximation and give results which are nearly as accurate a
s MP2 calculations.