Accurate determination of molecular structure and vibrational force constants by computation

Abstract

Characterization of the crystal forces that alter the geometry and vibrations of a molecule when it goes from the free to the solid state requires a comparison of the relevant properties between gas phase studies (usually electron diffraction, microwave spectroscopy, orab initio computation) and solid state experiments (usually x-ray or neutron diffraction). The present state ofab initio computation is reviewed with emphasis on the requirement for high accuracy and reliability, so that small alterations in the crystal can be detected, and on the desirability of carrying out the computations on as large systems as possible.