MB3P2S10 (M = Rb, Cs): two new alkali metal thioboratephosphates with [B6P4S20] T3-supertetrahedra

Two new alkaline metal thioboratephosphates, RbB₃P₂S₁₀ and CsB₃P₂S₁₀, have been designed and fabricated by the flux method. The two compounds are composed of alkali metal polyhedral and [B₆P₄S₂₀] T3-supertetrahedral units, and crystallize in I4₁/a and R3̄c space groups, respectively. The results enrich the chemical diversity of chalcogenides, and give insights for the exploration of new functional materials in thioboratephosphates.