Pressure-induced structural transition, metallization, and topological superconductivity in PdSSe

Pressure not only provides a powerful way to tune the crystal structure of transition metal dichalcogenides (TMDCs) but also promotes discovery exotic electronic states and intriguing phenomena. Structural transitions from quasi-two-dimensional layered orthorhombic phase three-dimensional cubic pyrite phase, metallization, superconductivity under high pressure have been observed experimentally in TMDCs materials PdS2 PdSe2. Here, we report theoretical prediction pressure-induced evolutions PdSSe, an isomorphous intermediate material A series structural into then are revealed. The features same symmetry as ambient except for drastic collapsed interlayer distances striking changes coordination polyhedron. Furthermore, accompanied by variations semiconductor semimetal, which attributed bandwidth broaden orbital-selective mechanisms. Especially, PdSSe is distinct PdSe2 breaking inversion mirror-plane symmetries, showing similar pressure, originated strong electron-phonon coupling interactions concomitant with topologically nontrivial Weyl high-fold Fermions. intricate interplay between lattice, charge, orbital degrees freedom well these compounds will further stimulate wide interest explore physics materials.