Lithium fluoride (LiF) is a typical ionic solid, and at the same time a typical polymorphic (multi-phase) material. Its phase diagram contains two solid phases, B1 (rock salt) and B2 (CsCl), which are typical of ionic solids. The phase diagram of LiF was suggested by Smirnov. We have carried out extensive study of the properties of LiF using one of the most recent versions of VASP (Vienna Ab initio Simulation Package) which allows one to carry out calculations on ionic solids; more detail will be presented elsewhere.