Temperature dependence of dynamical correlation in liquid lithium

The temperature dependence of dynamical variables, the velocity correlation function (VACF), the power spectrum (PS) and the mean square displacement (MSD) of liquid lithium at T= 470 K, 725 K, 843 K and 1000 K are studied by static harmonic-well approximation. The effective interatomic potential for liquid lithium is computed using our recently proposed model potential with the dielectric function of Sarkar et al. It is observed that for the higher temperature, the VACF furnishes very short memory than at melting temperature. The increase in the temperature decays the VACF slowly and also decreases the back scattering of atoms. The increase in the temperature increases the flatness of the shoulder of the power spectrum. The result of the MSD concludes that the presence of the vibrating component in the atomic motion decreases with increasing T.