  By means of first-principles density-functional theory calculations, we
investigate the role of hydrostatic pressure on the electronic structure of Td
(Pmn21 ) and 1T" (Pm) phases of Weyl semimetal Mo0.5 W0.5 Te2 , which is a
promising material for phase-change memory technology and superconductivity. We
particularly focus on changes occurring in the distribution of the gapless Weyl
points (WPs) within 0 to 45 GPa pressure range. We further investigate the
structural phase transition and lattice dynamics of the Td and 1T" phases
within the aforementioned pressure range. Our calculations suggest that both
the Td and 1T" phases of Mo0.5 W0.5 Te2 host four WPs in their full Brillouin
zone at zero pressure. The total number of WPs increases to 44 (36) with
increasing pressure via pair creation up to 20 (15) GPa for the T d (1T 00 )
phase, and beyond this pressure pair annihilation of WPs starts occurring
leaving only 16 WPs at 45 GPa in both phases. The enthalpy versus pressure data
reveal that the 1T 00 phase is more favorable below the critical pressure of
7.5 GPa, however, beyond this critical pressure the Td phase becomes
enthalpically favorable. We also provide the calculated x-ray diffraction
spectra along with the calculated Raman- and infrared-active phonon frequencies
to facilitate the experimental identification of the studied phases.
