Piecewise Polynomial Potential Partitioning (P4) Software

Tutorial

The P4 package is a set of software tools that automate the process of free energy calculation of solid phases with phonon instabilities that exist above certain temperatures due to dynamic stabilization. This software is based on the P4 method, which has been developed by Dr. Sara Kadkhodaei under supervision of Prof. Axel van de Walle. For a detailed description of the P4 method theory refer to the following papers:

  1. Sara Kadkhodaei, Qi-Jun Hong, and Axel van de Walle. "Free energy calculation of mechanically unstable but dynamically stabilized bcc titanium." Phys. Rev. B, 95:064101, Feb 2017. bibtex
  2. Sara Kadkhodaei and Axel van de Walle. "First-principles calculations of thermal properties of the mechanically unstable phases of the PtTi and NiTi shape memory alloys." Acta Materialia, 147:296 – 303, 2018. bibtex

For a detailed description of how to use the P4 package and examples, refer to the following paper:

  1. Sara Kadkhodaei and Axel van de Walle. "Software tools for thermodynamic calculation of mechanically unstable phases from first-principles data". Computer Physics Communications 2019 bibtex

The P4 package consists of five different modules including auglat, genrndstr, vcminimizer, vcrelax_vasp and mcmc. Refer to manual page and command line option for details.