calphy(pronounced cal-phee) is a Python library and command line tool for calculation of free energies. It uses LAMMPS as the molecular dynamics driver to enable calculation of free energies using thermodynamic integration in a completely automated and efficient manner. The various methods that calphy can perform are:
and
for both solid and liquid phases at the given thermodynamic conditions using non-equilibrium Hamiltonian interpolation.
and
, temperature dependence of Gibbs and Helmholtz free energies using the reversible scaling approach.
- Calculation of solid-solid or solid-liquid phase transition temperatures.
- Calculation of specific heat
as a function of temperature.
- Calculation of
and
for multicomponent systems using alchemical transformations.
- Upsampling calculations.
Calphy works with all interatomic potentials implemented in LAMMPS and can obtain reliable results with low error bars in as low as 50 ps of simulation time with less than 3000 atoms. More information about the methods in calphy can be found in the associated publication.
-
Read the
calphyinstallation instructions and documentation including examples here. -
For a description of the methods and algorithms implemented in
calphy, please see the associated publication. -
For a set of examples presented in the
calphypublication, please see here.
If you find calphy useful, please consider citing:
Menon, Sarath, Yury Lysogorskiy, Jutta Rogal, and Ralf Drautz.
“Automated Free Energy Calculation from Atomistic Simulations.”
Physical Review Materials 5(10), 2021
DOI: 10.1103/PhysRevMaterials.5.103801
Download bibtex here
calphy is published and distributed under the Academic Software Licence v1.0 (ASL), a reciprocal licence whose core terms match the GNU GPLv2 but which permits academic non-commercial use only. It is an available-source, not an open-source, licence. See LICENSE for the full terms.
If you intend to use calphy commercially, you need a separate commercial licence. Please contact sarath.menon@ruhr-uni-bochum.de to enquire about commercial use rights.
Releases up to and including 2.0.1 were distributed under a split ASL / BSD-3-Clause licence (and earlier releases under the GNU GPL). Those grants continue to apply to the versions they were published with; from 2.1.0 onwards calphy is ASL only.
Note that calphy drives LAMMPS, which is licensed separately under the GNU GPLv2. calphy does not include LAMMPS.
