Search algorithm based on the phase trees of the multicomponent systems for compositions with given properties (melting temperature, melting enthalpy, electroconductivity, etc.) was developed. The algorithm was evaluated on a tetracomponent reciprocal system Li,K||F,Br,WO4. Ternary system LiF–LiBr–Li2WO4, ternary reciprocal system Li,K||Br,WO4, stable secant triangle LiF–Li2WO4–KBr and stable tetrahedron LiF–LiBr–Li2WO4–KBr were experimentally investigated.