EFFICIENT COMPUTATION OF POTENTIAL-ENERGY FIRST AND 2ND DERIVATIVES FOR MOLECULAR-DYNAMICS, NORMAL-COORDINATE ANALYSIS, AND MOLECULAR MECHANICS CALCULATIONS
Re. Tuzun et al., EFFICIENT COMPUTATION OF POTENTIAL-ENERGY FIRST AND 2ND DERIVATIVES FOR MOLECULAR-DYNAMICS, NORMAL-COORDINATE ANALYSIS, AND MOLECULAR MECHANICS CALCULATIONS, Macromolecular theory and simulations, 5(4), 1996, pp. 771-788
By using two- and three-body internal coordinates and their derivative
s as intermediates, it is possible to enormously simplify formulas for
three- and four-body internal coordinates and their derivatives. Usin
g this approach, simple formulas are presented for stretch (two-body),
two types of bend (three-body), and wag and two types of torsion (fou
r-body) internal coordinates and their first and second derivatives. T
he formulas are eminently suitable for economizing molecular dynamics
and molecular mechanics calculations and normal coordinate analysis of
complicated potential energy surfaces. Efficient methods for computin
g derivatives of entire potential energy terms, and in particular cros
s terms or terms with switching functions, are presented.