also: KBi(WO4)2

KBiW crystal is known since 1975 (Klevtsov, Koseeva and Khartzenko).

KBiW crystallizes in monoclinic $I2/a$ space group (2/m point group). Its conicity of 16.2mrad is measured at 633nm. The transparency range is from 0.34$\mu$m to 5.7$\mu$m.

KBiW crystal can be doped with laser active ions from the lanthanide group, as well as with Cr3+.

KBiW and its isostructural analogs have very high resistance to humidity, possess good thermomechanical properties and excellent optical quality.