Ab initio study of superconducting hexagonal Be2Li under pressure

Following the recent interest on lithium alloys under pressure, we present first-principles calculations of the electronic band structure and lattice dynamics for the MgB2-like layered Be2Li at 80 GPa. Under pressure, the increasing electronic localization reduces the effective dimensionality of Be2Li, showing both two-dimensional and one-dimensional conducting electronic channels. The numerical results reveal the presence of an ultrasoft strongly anharmonic B-2g phonon mode associated to the atomic buckling in the layers, which shows a high electron-phonon interaction near the zone center and (besides the moderately coupled E-2g in-plane and A(1g) interlayer Be modes) is responsible for a predicted superconducting transition around 2.5 K.