Estimation of Gruneisen parameter and associated derived quantities

In the present computations the values of gamma (th)(g), gamma (g)', Q (d l n D/dP)T, and C-v for several substances including C-60 have been calculate d. In most cases the present calculated values are in good agreement with l iterature values. The authors found that in the case of the Anderson Grunei sen parameter delta (T) is slightly on the higher side. The value of Q is n egative for C-60 and for Cd. The values of Q, the second Gruneisen constant for all substances for which calculations have been made are found to be n egative except in the case of Hg. In general gamma (g)' is small as expecte d. The pressure derivative of the diffusion coefficient for Hg is in excell ent agreement with experiment. The authors have made similar calculations o f the quantities namely gamma (g)', Q, and delta (T) for C-60 The values of metallic Cd and that of C-60 which is classified as a metal give negative values. It is too early to conclude that all metals give negative values fo r Q until ample data is got. In this connection White et al., suggested tha t gamma (ex)(g) (external) for C-60 is significant and hence the authors us ed this value since they obtained for gamma (th)(g) nearly the same value b y two entirely different methods.