New noncentrosymmetric sulfides promising for high optical nonlinearity

A sets of 375 noncentrosymmetric simple and binary sulfides have been observed and classified. The elliptical regions on the plane of the shortest chemical bond lengths between cations and sulphur as coordinates have been defined. The crystals without center of inversion may be located only in these regions. Interrelation between nonlinear optical susceptibility /spl chi/ and chemical bonding in sulfides has been considered. The intervals of the shortest bond lengths cation-anion optimal for high rank /spl chi/ have been estimated for the compounds.