qha: A Python package for quasi-harmonic free energy calculation for multi-configuration system

ORAL

Abstract

The quasi-harmonic approximation (QHA) offers an effective way of calculating the thermodynamic properties of many crystalline solids at high pressures and temperatures. In some cases, e.g., solid solutions or partially disordered systems such as H2O ice-VII, the system has numerous symmetrically distinct configurations. Here we present a Python package, qha, which can calculate the equation of state and various thermodynamic properties of both single- and multi-configuration crystalline systems in the framework of the QHA. This code has a wide range of applications, including, but not limited to, order-disorder phase transitions [1], solid solutions [2], complex defect stability [3], etc. Apart from its versatility, qha has been tested to be both accurate and computationally efficient. It can also be used as an all-in-one executable or taken apart into stand-alone functions, increasing its usability.

[1] K. Umemoto et al., Chemical Physics Letters. 499, 236–240 (2010).
[2] G. Shukla, R. M. Wentzcovitch, Physics of the Earth and Planetary Interiors. 260, 53–61 (2016).
[3] T. Qin et al., American Mineralogist. 103, 692–699 (2018).

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Presenters

  • Qi Zhang

    Department of Applied Physics and Applied Mathematics, Columbia University in the City of New York, Department of Applied Physics and Applied Mathematics, Columbia University in the City of New York, 500 W. 120th St., Mudd 200, MC 4701 New York, NY 10027, USA, Department of Applied Physics and Applied Mathematics, Columbia University in the City of New York, 500 W. 120th St., Mudd 200, MC 4701 New York, NY 10027, USA.

Authors

  • Qi Zhang

    Department of Applied Physics and Applied Mathematics, Columbia University in the City of New York, Department of Applied Physics and Applied Mathematics, Columbia University in the City of New York, 500 W. 120th St., Mudd 200, MC 4701 New York, NY 10027, USA, Department of Applied Physics and Applied Mathematics, Columbia University in the City of New York, 500 W. 120th St., Mudd 200, MC 4701 New York, NY 10027, USA.

  • Tian Qin

    Department of Earth Sciences, University of Minnesota

  • Koichiro Umemoto

    Earth-Life Science Institute, Tokyo Institute of Technology, ELSI, Tokyo Institute of Technology

  • Renata Wentzcovitch

    Department of Applied Physics and Applied Mathematics, Columbia University in the City of New York, Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory (LDEO), and Applied Physics and Applied Mathematics (APAM), Columbia University in the City o, Department of Applied Physics and Applied Mathematics, Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory, Columbia University, Columbia University, Department of Applied Physics and Applied Mathematics, Columbia University, Applied Physics and Applied Mathematics and Department of Earth and Environmental Sciences, Lamont Doherty Earth Observatory, Columbia University, Department of Applied Physics and Applied Mathematics, Columbia University in the City of New York, 500 W. 120th St., Mudd 200, MC 4701 New York, NY 10027, USA, Department of Applied Physics and Applied Mathematics, Columbia University in the City of New York, 500 W. 120th St., Mudd 200, MC 4701 New York, NY 10027, USA., Department of Applied Physics and Applied Mathematics; Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory, Columbia University, 10027, USA