For two other boron pnictides, the intersections of the E(V) curves of zb-BX and qtz BX are observed at V/V 0 = 0.724 for zb-BSb (Fig. ) and V/V 0 = 0.763 for zb-BBi (Fig. ). The corresponding pressures, 71 GPa and 51 GPa, were estimated using the most reliable B 0 values calculated in framework of the thermodynamic model (Table ), while B 0 ʹ values were fixed at 4.