Electronic topological transition in Nb3Al under compression: An ab initio study

Very recently Yu et al. studied the structural stability of Nb3Al over a range of pressure up to 39.5 GPa. They have noticed an anomaly in the pressure volume plot beyond 19.2 GPa. The physical mechanism is not explained by them. The electronic structure is obtained as function of pressure by the all electron full potential linear augmented plane wave method. The energy dispersion curves are plotted. From the plot we observe that the 'd' like band of Nb at the zone center moves under pressure which may be the possible reason for the isostructural phase transition reported experimentally. The elastic properties are also calculated which also confirms the transition.