cij: A Python code for quasiharmonic thermoelasticity

The Wu-Wentzcovitch semi-analytical method (SAM) is a concise and predictive formalism to calculate the high-pressure high-temperature (high-PT) thermoelastic tensor (Cij) of crystalline materials. This has been successfully applied materials across different crystal systems in conjunction with ab initio calculations static elastic coefficients phonon frequencies. Such results have offered first-hand insights into composition structure Earth's mantle. Here we introduce cij package, Python implementation SAM-Cij formalism. It enables thermoelasticity calculation be initiated from single command fully configurable settings file work solids within any system. These features allow on personal computer easily integrated as part high-throughput workflows. show performance this code for three minerals at their relevant PTs: diopside (monoclinic), akimotoite (trigonal), bridgmanite (orthorhombic). Program title: CPC Library link program files: https://doi.org/10.17632/b8xf5jh5s8.1 Developer's repository link: https://github.com/MineralsCloud/cij Licensing provisions: GNU General Public License 3 Programming language: Nature problem: Experimental measurements full under conditions are challenging susceptible uncertainties. Computations based conventional density functional theory (DFT) plus quasiharmonic approximation (QHA) or molecular dynamics (AIMD) methods computationally extremely demanding, especially low symmetries because revaluation free energy strained configurations. Solution method: Based proposed by Wu Wentzcovitch [1], developed handy that only needs static-state vibrational states several equilibrium configurations pressure points input thermal elasticity. avoids reevaluation can all systems. Z. Wu, R.M. Wentzcovitch, Phys. Rev. B 83 (2011) 184115.