Series of topological phase transitions in TiTe2under strain

First-principles calculations are performed to investigate the topological properties of TiTe${}_{2}$ under hydrostatic pressure, uniaxial strain, and biaxial strain. It is found that the system is unusually accessible to strain effects and the first compound that under hydrostatic pressure (up to experimentally reasonable 30 GPa) is subject to a series of four topological phase transitions, which are related to band inversions at different points of the Brillouin zone. Therefore, TiTe${}_{2}$ enables experimental access to all these transitions in a single compound.