Singh, J.; Errandonea, D.; Kanchana, V.; Vaitheeswaran, G. Pressure-Driven Responses in Cd2SiO4 and Hg2GeO4 Minerals: A Comparative Study. Crystals2024, 14, 538.
Singh, J.; Errandonea, D.; Kanchana, V.; Vaitheeswaran, G. Pressure-Driven Responses in Cd2SiO4 and Hg2GeO4 Minerals: A Comparative Study. Crystals 2024, 14, 538.
Singh, J.; Errandonea, D.; Kanchana, V.; Vaitheeswaran, G. Pressure-Driven Responses in Cd2SiO4 and Hg2GeO4 Minerals: A Comparative Study. Crystals2024, 14, 538.
Singh, J.; Errandonea, D.; Kanchana, V.; Vaitheeswaran, G. Pressure-Driven Responses in Cd2SiO4 and Hg2GeO4 Minerals: A Comparative Study. Crystals 2024, 14, 538.
Abstract
The structural, elastic, and electronic properties of orthorhombic Cd2SiO4 and Hg2GeO4 were examined under varying pressure conditions using first-principles calculations based on densi-ty-functional theory employing the projector augmented wave method. The obtained cell pa-rameters at 0 GPa were found to align well with existing experimental data. We delved into the pressure-dependence of normalized lattice parameters and elastic constants. In Cd2SiO4, all lat-tice constants decreased as pressure increased, whereas in Hg2GeO4, parameters a and b de-creased while parameter c increased under pressure. Employing the Hill average method, we calculated the elastic moduli and Poisson’s ratio up to 10 GPa, noting an increase with pressure. Evaluation of ductility/brittleness under pressure indicated both compounds remained ductile throughout. We also estimated elastic anisotropy and Debye temperature under varying pres-sures. Cd2SiO4 and Hg2GeO4 were identified as indirect band gap insulators, with estimated band gaps of 3.34 eV and 2.09 eV, respectively. Interestingly, Cd2SiO4 exhibited a significant increase in band gap with increasing pressure, whereas the band gap of Hg2GeO4 decreased under pres-sure, revealing distinct structural and electronic responses despite their similar structures.
Keywords
Thenardite-type mineral; First-principles calculations; High-pressure study; Electronic band structure
Subject
Physical Sciences, Condensed Matter Physics
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.