The title compounds, LiKB4O7 (LKB4) and LiRbB4O7 (LRB4), are newly develope
d nonlinear optical crystals containing two kinds of anionic groups, (B3O8)
(7-) and (B5O10)(5-). The (B3O8)(7-) groups form infinite spiral chains par
allel to the [1 0 0] direction, which are interconnected by sharing oxygen
atoms with (B5O10)(5-) groups. (C) 2001 Elsevier Science B.V. All rights re
served.