The Origin of Nonlinearities in K[B5O6(OH)4] · 2 H2O Crystal
Abstract
In this paper the origin of nonlinearities of the K[B5O6(OH)4] · 2 H2O (KB5) crystal has been investigated from a comprehensive view-point by using the bond-valence theory of complex crystals. The results of the calculation (d31 = —1.18 × 10—10 esu, d32 = 0.20 × 10—10 esu, and d33 = —1.03 × 10—9 esu) are in good agreement with experimental data. For the first time we pointed out that its nonlinearities come from the H(2)–O(2) bonds and the [B5O6(OH)4]— group, and estimated its larger nonlinear optical (NLO) coefficient d33.