Abstract
The k-vector dispersion of vibrational excitations in benzoic acid crystals was calculated, based on force constants determined from periodic DFT calculations in a simulation box composed of four unit cells of the crystal. To compensate for the underevaluation of intermolecular attractive forces in DFT calculations, the geometry of the unit cell, measured at low temperature, was imposed. Inelastic neutron spectra, determined from the corresponding density of states, agree well with measured spectra in the region of the in-plane and out-of-plane bending modes of the carbonyl group, where the dispersion is noticeable. This result makes unnecessary alternative explanations, based on unphysical assumptions, for the structure observed in the spectra. The good agreement between experiment and calculation validates the approach used here to determine the intermolecular potential.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.