“…The study of inorganic borates is motivated by their possible non-linear optical properties, transparency in a wide range of wavelengths, high laser-damage tolerance, piezoelectricity and luminescent and other useful properties for technical applications of the respective compounds. For example, -BaB 2 O 4 (Chen et al, 1985), LiB 3 O 5 (Chen et al, 1989), CsB 3 O 5 (Sasaki et al, 2000), Sr 2 Be 2 B 2 O 7 (Chen et al, 1995), K 5 Ba 10 (BO 3 ) 8 F (Liu et al, 2016), PbB 4 O 7 (Bartwal et al, 2001), Pb 2 B 5 O 9 X (X = Cl, Br, I) (Huang et al, 2010) or Ba 3 Sr 4 (BO 3 ) 3 F 5 (Zhang et al, 2009) have been studied because of their second-order ISSN 2056-9890…”