Introduction of the Cl–anion in the borate systems generates a new perovskite-like phase, K3B6O10Cl, which exhibits a large second harmonic response, about four times that of KH2PO4 (KDP), and is transparent from the deep UV (180 nm) to middle-IR region. K3B6O10Cl crystallizes in the noncentrosymmetric and rhombohedral space group R 3 m. The structure consists of the A-site hexaborate [B6O10] groups and the BX3 Cl-centered ...
[Khanna, Ish K.; Weier, Richard M.; Yu, Yi; Collins, Paul W.; Miyashiro, Julie M.; Koboldt, Carol M.; Veenhuizen, Amy W.; Currie, Jerry L.; Seibert, Karen; Isakson, Peter C. Journal of Medicinal Chemistry, 1997 , vol. 40, # 11 p. 1619 - 1633]