The Triclinic Room-Temperature Modification of K₂MgWO₂(PO₄)₂

K₂MgWO₂(PO₄)₂ [dipotassium magnesium tungsten dioxide bis(phosphate); abbreviated formula: KMgWP], a new compound crystal-chemically derivable from the well known nonlinear optical crystal KTiOPO₄ (KTP), undergoes at least five phase transitions between its melting point (T_m = 1068 K) and room temperature. KMgWP's triclinic room-temperature structure (space group P1) can be described as a slightly distorted modification of its tetragonal high-temperature phase (T > 782 K), which is isostructural with K₂NiWO₂(PO₄)₂ (KNiWP, space group P4_1,32₁2).

-1