# Soft modes and negative thermal expansion in Zn(CN)2 from Raman spectroscopy and first-principles calculations

@article{Ravindran2007SoftMA,
title={Soft modes and negative thermal expansion in Zn(CN)2 from Raman spectroscopy and first-principles calculations},
author={T R Ravindran and A. Arora and S. Chandra and M. C. Valsakumar and N. C. Shekar},
journal={Physical Review B},
year={2007},
volume={76},
pages={054302}
}
We have studied $\mathrm{Zn}{(\mathrm{C}\mathrm{N})}_{2}$ at high pressure using Raman spectroscopy and report Gr\"uneisen parameters of the soft phonons. The phonon frequencies and eigenvectors obtained from ab initio calculations are used for the assignment of the observed phonon spectra. Out of the 11 zone-center optical modes, 6 modes exhibit negative Gr\"uneisen parameter. The calculations suggest that the soft phonons correspond to the librational and translational modes of \$\mathrm{C… Expand
24 Citations