Atomic Force Constants in Some First Row Compounds

By analysis of a vibrational frequency sum rule a set of force constants characteristic of H, C, N, O, and F atoms was found. These quantities, called atomic force constants, have the remarkable property of being independent of the details of molecular geometry or bonding multiplicity. Hence, it is possible to compute the sums of the squares of the normal frequencies of compounds involving these elements without explicit prior knowledge of their structures.