Fig. 4: Theoretical structure and band gap comparison with pressure.
a–c MnPS3 crystal structures with a, monoclinic (C2/m) staggered P-dimer (SPD) structure at ambient pressure, b hexagonal (\(P\bar{3}1m\)) aligned P-dimer (APD) structure in the intermediate-pressure regime (5 ≲ P ≲ 45 GPa), and c aligned P-chain (APC) structure with the monoclinic space group (C2/m). In the APD and APC structure, phosphorus ions in neighboring layers are located on top of each other, forming a chain-like structure in the APC phase above 45 GPa. d–e k-resolved and orbital-projected spectral functions calculated with the structures shown in b and c, respectively, showing the discontinuous nature of the APD to APC transition. f Evolution of the band gap size (obtained from DMFT) as a function of pressure, where the red and green curves represent the band gaps of the SPD and APD/APC structures, respectively. The blue dash-dotted curve shows the anticipated gap size of the APD phase between 28 and 40 GPa, where the gap closes around 30 GPa. g Calculated optical conductivity of MnPS3 in the APD and SPD structures at ambient conditions and under pressure (P = 18.9 and 21.2 GPa, corresponding to the APD and SPD structures, respectively).
