ANALYTIC 2ND DERIVATIVES OF THE GRADIENT-CORRECTED DENSITY-FUNCTIONALENERGY - EFFECT OF QUADRATURE WEIGHT DERIVATIVES

Harmonic vibrational frequencies of several small molecules were calcu lated using analytic second derivatives of the B-LYP energy for a vari ety of quadrature grids. It is demonstrated that proper inclusion of t he weight derivative terms is required to ensure the calculations are well-behaved, especially for smaller grids.