Electronic phase transition and amorphization in AuIn2 at high pressure

High-resolution angular-dispersive x-ray diffraction shows that the intermetallic compound AuIn2 retains its initial CaF2 structure to pressures of 23 GPa. We observe continuous broadening of diffraction lines with pressure, leading to amorphization at 24 GPa. The pressure-volume equation of state exhibits an anomaly around 2.7 GPa, in agreement with previous findings and not attributable to nonhydrostaticity. Instead, ab initio plane-wave self-consistent field calculations indicate that the observed anomaly is associated with topological changes in the electronic band structure under pressure.