Abstract
Computer simulations of thermal motions in molecular solids have been made using a Monte Carlo MC program. Certain results of the simulations are best shown by means of computer movies, as will be noted when appropriate. Problems studied to date which will be emphasized here are : relaxation around porphyrin substitutional defects and vacancy defects in n-octane matrices, rotational motions in solid benzene1 and growth of benzene microcrystals.