Real and virtual polymorphism of titanium selenide with robust interatomic potentials

Abstract

The first successful pairwise potential for a layered material, TiSe2, 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 AX2 metastable phases using ab initio derived data. From the initial survey, the ground state 1T-TiSe2 structure remains the lowest enthalpy phase in a wide range of pressures (0 to 25 GPa), which leaves open questions about the nature of a reported unknown high-pressure phase.