Fig. 1

Crystal structures and parameters of the high and low pressure phases. a Crystal structure of V_0.9PS₃ at 11 kbar—the LP phase and b at 177 kbar—the HP-I phase. The HP-I structure has β close to 90° so atoms in each plane are aligned with their equivalents in neighboring planes. c, d Projections of the same structures along the b axis. e Phase fractions of the LP (blue circles) and HP-I (red crosses) phases as a function of pressure. f Refined unit cell volumes for each phase. The LP phase volume is plotted as blue circles and the HP-I as red crosses. The two phases coexist over a wide pressure range, rather than an abrupt transition between the two, and the unit cell volume shows no jumps or sudden transitions