Work

Anisotropic temperature-dependent lattice parameters and elastic constants from first principles

Year: 2025

Type: article

Abstract: We present an efficient implementation of the Zero Static Internal Stress Approximation (ZSISA) within the Quasi-Harmonic Approximation framework to compute anisotropic thermal expansion and elastic constants from first principles. By replacing the costly multidimensional minimization with a gradient-based method that leverages second-order derivatives of the vibrational free energy, the number of required phonon band structure calculations is significantly reduced: only six are needed for hexagonal, trigonal, and tetragonal systems, and 10–28 for lower-symmetry systems to determine the temperature dependence of lattice parameters and thermal expansion. This approach enables accurate modeling of anisotropic thermal expansion while substantially lowering computational cost compared to standard ZSISA method. The implementation is validated on a range of materials with symmetries from cubic to triclinic and is extended to compute temperature-dependent elastic constants with only a few additional phonon band structure calculations.

Source: npj Computational Materials

DOI: 10.1038/s41524-025-01765-5

Authors: Samare Rostami, Matteo Giantomassi, Xavier Gonze

Institutions: European Theoretical Spectroscopy Facility, UCLouvain

Language: English

Topic: Thermal Expansion and Ionic Conductivity

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,490

Funder: Fonds De La Recherche Scientifique - FNRS