We have investigated anomalous lattice behavior of metal organic framework compound AgC8N5on application of pressure and temperature using ab-initio density functional theory calculations. The van der Waals dispersion interactions are found to play an important role in structural optimization and stabilization of this compound. Our ab-initio calculations show negative linear compressibility (NLC) along the c-axis of the unit cell. The ab-initio lattice dynamics as well as the molecular dynamics simulations show large negative thermal expansion (NTE) along the c-axis. The mechanism of NLC and NTE along the c-axis of the structure is governed by the dynamics of Ag atoms in the a-b plane. The NLC along the c-axis drives the NTE along that direction.
@article{arxiv.1804.07551,
title = {Density Functional Studies Reveal Anomalous Lattice Behavior in Metal Cyanide, AgC8N5},
author = {Baltej Singh and Mayanak K. Gupta and Ranjan Mittal and Samrath L. Chaplot},
journal= {arXiv preprint arXiv:1804.07551},
year = {2018}
}