Structural analysis of nonlinearities of Ca4ReO(BO3)3 (Re = La, Nd, Sm, Gd, Er, Y)

4ReO(BO3)3 (CReOB, Re=La, Nd, Sm, Gd, Er, and Y) have been theoretically predicted. The d11 tensor coefficient of CReOB is predicted to be -11 d36(KDP), which is the largest dij tensor that has been found in borate crystals. From the structural characteristic of CReOB, we find the isolated BO33- clusters play a dominant role in contributions to the total nonlinearity, and the largest d11 tensor of CReOB-type crystals is also ascribed to these BO33- clusters. We also find the NLO property of this family does not change dramatically for different rare-earth elements. The details of the calculation of CGdOB only are presented.