Stochastic sampling of the isothermal-isobaric ensemble: Phase diagram of crystalline solids from molecular dynamics simulation

Author(s)

Cajahuaringa, Samuel ^[1] ; Antonelli, Alex ^{[1, 2]}

Affiliation

^[1] Univ Estadual Campinas, UNICAMP, Inst Fis Gleb Wataghin, BR-13083859 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, UNICAMP, Ctr Computat Engn & Sci, BR-13083859 Campinas, SP - Brazil

• Document type: Journal article
• Source: Journal of Chemical Physics; v. 149, n. 6 AUG 14 2018.
• Web of Science Citations: 1

Abstract

A methodology to sample the isothermal-isobaric ensemble using Langevin dynamics is proposed, which combines novel features of geometric integrators for the equations of motion. By employing the Trotter expansion, the methodology generates a robust, symmetric, and accurate numerical algorithm. In order to show that the proposed method correctly samples the phase-space, simulations in the isotropic NPT ensemble were carried out for two analytical examples. Also this method lets us study a solid-solid phase transition by conducting a fully flexible-cell molecular dynamics simulation. Additionally, we present an efficient method to determine the Gibbs free energy in a wide interval of pressure along an isothermal path, which allows us to determine the transition pressure in a driven by pressure solid-solid phase transition. Our calculations show that the methodology is highly suitable for the study of the phase diagram of crystalline solids. Published by AIP Publishing. (AU)

• FAPESP's process: 16/23891-6 - Computer modeling of condensed matter
• Grantee: Alex Antonelli
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 10/16970-0 - Computational modeling of condensed matter: a multiscale approach
• Grantee: Alex Antonelli
• Support Opportunities: Research Projects - Thematic Grants