The physical properties of KRbAl2B2O7 have been considered in comparison with those of K2Al2B2O7 and Rb2Al2B2O7. The vibrational parameters of KRbAl2B2O7 have been measured by Raman spectroscopy as very similar to those of K2Al2B2O7. The electronic structures of KRbAl2B2O7 have been evaluated by X-ray photoelectron. spectroscopy and ab initio computations using CASTEP package. A noticeable refractive indices increase and small decrease of nonlinear optical properties have been found in KRbAl2B2O7 in reference to optical parameters of K2Al2B2O7. (c) 2012 Elsevier Ltd. All rights reserved.