First-principles study of zinc-blende to rocksalt phase transition in BP and BAs

The structural and electronic properties of BP and BAs are investigated by first-principles pseudopotential method. The calculations show the structural phase transition from zinc-blende (ZB) structure to rocksalt (RS) structure at the transition pressure of 142 GPa for BP and 134 GPa for BAs. The ZB phase of BP and BAs remains indirect gaps upon applying hydrostatic pressure, while RS phase of BP and BAs is semimetal at the transition pressure.