DFT Calculation for Elastic Constants of Tetragonal Structure of Crystalline Solids with WIEN2k Code: A New Package (Tetra-elastic)

摘要

Tetra-elastic is a new package for calculating the elastic constants of tetragonal structure. It iscompatible with the highly accurate all electron full potential linearized augmented plane wave pluslocal orbital [FP-(L)APW+lo] method as implemented in WIEN2k code. The package is releasedrecently; the package and the user guide are available on(http://www.wien2k.at/reg_user/unsupported/). In this paper we provide detail description of theformalism of calculating the elastic constants of tetragonal structure. To testify the accuracy of theTetra-elastic package several tetragonal structure compounds were used. The results show that thecalculated elastic constants using Tetra-elastic exhibit better agreement with the availableexperimental data than the previous theoretical results used different methods. In this package thesecond-order derivative E仴 of polynomial fit E E仴 of energy vs strains at zero strain 仴 0isused to calculate the tetragonal elastic constants.