Anharmonicity correction for kinetic isotope effect calculations involving hydrogen isotopes

Abstract

Depending upon the force field the anharmonicity correction for kinetic isotope effect calculations, based on simplified reacting systems representing a 1,2 hydride shift, may be large. For example, for deuterium and tritium kinetic isotope effects, calculated by means of the usual harmonic approximation, the anharmonicity correction is, at 300 K and for a particular force field, 0.74 or 0.66 respectively.