High-pressure behavior of LiBeH3 is investigated through ab initio total-energy calculations and evolutionary structure prediction simulations. Static enthalpy calculations indicate that the low-pressure phases of LiBeH3 containing BeH4 tetrahedra transform into the GdFeO3 -type perovskite Pnma phase at 17 GPa and then at 140 GPa into the CaIrO3 -type postperovskite Cmcm phase, both of which contain BeH6 octahedra. LiBeH3 remains an insulator through all these transitions and up to the pressure of 530 GPa, above which it dissociates into LiH (space group Cmmm) and BeH2 (space group P4/nmm). Our results show that LiBeH3 remains insulating in a wide pressure range, which resolves the long-standing debate on the possibility of this compound becoming a superconductor at experimentally reachable static pressures.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 1 Apr 2009|