Pressure dependent topological, superconducting, optoelectronic and thermophysical properties of Ta2Se chalcogenide: Theoretical insights

Tetragonal Ta2Se is a layered, Ta-rich chalcogenide that departs from conventional MX2 transition-metal dichalcogenides by hosting dense Ta-Ta networks capped by Se square-net layers. Here, we present a unified first-principles investigation of hydrostatic-pressure tuning in Ta2Se from 0 to 10 GPa, connecting the structural response, mechanical stability, thermophysical indicators, bonding evolution, electronic and optical behavior, lattice dynamics and superconductivity within a single framework. The derived thermophysical descriptors corroborate a pressure-stiffened lattice: density increases, Debye temperature rises, melting temperature is elevated and minimum thermal conductivity increases, whereas the Grüneisen parameter remains within a narrow window, suggesting no anomalous anharmonic softening. Bond population metrics and electron-density-difference analysis revealed a mixed metallic-covalent bonding picture dominated by a robust Ta-Ta metallic backbone, accompanied by pressure-strengthened Ta-Se hybridization. Electronic-structure calculations show persistent metallicity under compression; pressure broadens bands, reduces density of states at the Fermi level, reshapes the Fermi surface and points to a possible Lifshitz-type reconstruction without symmetry breaking. The optical response remained metallic with Drude-like low-energy behavior and pressure-tunable spectral features. The phonon dispersions exhibit no imaginary modes, confirming dynamical stability. Electron-phonon coupling calculations classify Ta2Se as a weak-coupling, phonon-mediated superconductor with Tc around 3.9 K, consistent with available experiments and establish pressure as a practical control knob for stability and superconductivity-relevant descriptors in this metal-rich layered platform.