Phonon densities of states of Sn to 64 GPa

We measured lattice dynamics of 3 phases of Sn to 64 GPa at ambient temperature by NRIXS and compare the results with DFT computations using the direct force method and all-electron PAW method as implemented in the VASP code. Calculations with either GGA or LDA approximations gave similar results. Other properties calculated from the results include: the Lamb-Mossbauer factor; the mean force constant; vibrational contributions to the Helmholtz free energy; the high and low temperature Debye temperatures; the Debye average phonon velocity; and the Debye-Gruneisen parameter. At all pressures, experimental and theoretical DOS agree well.