Anharmonicity in Crystal Vibrations

摘要

A scheme for the calculation of anharmonicity in crystal vibrations is developed for crystals with one molecule per unit cell. This method is applied tonhyphen;hexane crystal. It is found that the contribution from anharmonicity can be very important in lattice vibrations of molecular crystals. Hence, the use of harmonic crystal vibrations for evaluation of nonbonded potentials without an anharmonicity correction can lead to an inconsistent potential.