Marvin Poul

L Huber, E Bitzek, J Neugebauer 

Computational Materials Design, MPI für Eisenforschung, Düsseldorf, Germany

The Mg-Al binary phase diagram via moment tensor potentials: A workflow

We develop an automatic workflow to calculate the phase diagram of binary systems from interatomic potentials in the quasi-harmonic and dilute approximation.

Given a set of reference structures the workflow classifies them into solid solution phases and phases with significant chemical ordering.  Solid solutions are treated in the regular solution model using special quasirandom structures to extract the mixing enthalpy.  For ordered phases the workflow constructs possible point defects automatically and calculates the mixing enthalpy in the dilute solution model.  While this does not yield the most accurate representation of the free energy, the involved calculations are fast and straightforward and enable this method to be used as a quick reference for a large number of systems.

We demonstrate this workflow using a Moment Tensor Potential fitted for Mg/Al system.