ABSTRACT
The paper is aimed to understand the key phonon modes that are responsible for the temperature dependent structural phase transition and negative thermal expansion of Hg2Cl2 compound for the first time with the aid of density functional theory and Born-Oppenheimer on the fly molecular dynamics calculations. The phonon dispersion spectra, phonon density of states and Grüneisen parameters for the body-centered tetragonal and base-centered orthorhombic phases of the compound have been explored in detail. The order parameter associated with the phase transition and its nature has also been reported herewith. We believe that the present study will not only help for futuristic designs of improved functionalized systems with Hg2Cl2 compound but also can augment their applications in thermoelectric conversion systems, fibre-optic communications, thermal expansion compensators and in fuel cells.
Acknowledgements
Authors would like to thank the Department of Physics, Jadavpur University for availing the computational facility through DST-FIST programme. Swarup Ghosh truly acknowledges the University Grants Commission (UGC), Government of India for providing the senior research fellowship (NET) award.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Data availability statement
Data are available on valid request from the corresponding author.