A ternary metal selenide KInSe~2 has been synthesized by use of the reactive molten salt method. The reactants with molar ratio of n (K~2Se~3) : n(In) : n(Se)=1 : 1 :5 were reacted at 500℃ for 5 days. The crystal structure of KInSe~2 was determined by X-ray structure analysis. KInSe~2 belongs to monoclinic system with space group C2/c. The unit cell parameters are a=1.414(2) nm, b=1.1410(2) nm, c=1.5586 (3) nm, β=100.60(3)°, Z=16. KInSe~2 is a layered crystal containing 2D network of ^2~∞[InSe~2]^- anions and K^+ cations. The layers are packed in the sequence ABAB in the crystal. There are two crystallographically independent In atoms, both of which are coordinated to four μ~2 Se atoms to form slight distorted tetrahedra. Of the five crystallographically independent Se atoms, Se(3) and Se(5) are located on 2-fold axes (4e). The K^+ ions are six-coordinated to Se.

Key words: STRUCTURE CHARACTERISTICS, CRYSTAL STRUCTURE, SOLID PHASE REACTION