Experimental work has shown that YLi F4 has a first phase transition from the ambient pressure scheelite to a fergusonite structure at 10 GPa, and a second one at 17 GPa to an unresolved structure. Theoretical work has proposed either M - or M′ -fergusonite as the second structural phase, and wolframite or a P 21 c -symmetry structure as the third. In this ab initio study, we find that the M′ -fergusonite structure is a better candidate for the second phase of YLi F4, and propose a new structure with Cmca symmetry as the third. © 2006 The American Physical Society.
