Force constant calculations of methyl mercuric chloride and methyl-d3 mercuric chloride

Abstract

The infra-red and Raman spectra of solid CH₃HgCl and CD₃HgCl are reported. Force constants are calculated on the basis of an almost general harmonic force field which was arrived at by systematic modifications of force constants initially assumed, utilizing the Jacobian matrix as a criterion for the importance of individual terms in the potential energy. All the constants which significantly affect the calculated frequencies were taken into account. The force constants obtained produce frequencies in an agreement better than 1 %, while a comparison with the available Coriolis zeta constants indicates a fair agreement. For the improvement of the normal coordinates (L matrix), frequency-insensitive off diagonal force constants neglected in the treatment are required.