Real and virtual polymorphism of titanium selenide with robust interatomic potentials

Abstract

The first successful pairwise potential for a layered material, TiSe$_2$, has been parameterised to fit the experimental data, using a genetic algorithm as the optimisation tool for the parameters of the interatomic potential. This potential has been tested on a wide range of hypothetical isomorphous AX$_2$ metastable phases using ab initio derived data. From the initial survey, the ground state 1T-TiSe$_2$ structure remains the lowest enthalpy phase in a wide range of pressures (0 to 25 GPa), which leaves open a question about the unknown high pressure phase(s) nature.