Estimation of Bi+ monocation crystal ionic radius by quantum chemical simulation

The series of quantum chemical calculations for model molecular system, consisted of monocation Me+ (Bi+ or alkali metal cations), surrounded by two weakly coordinating BF 4 - anions were performed. It was demonstrated, that in this model system, the Me + - BF 4 - distances, which corresponds to ground state electronic energy minimum are in good correlation with the values of Shannon crystal ionic radii for corresponding monocations. Taking advantage of this correlation it is possible to estimate the unknown crystal ionic radius of Bi+ monocation from CASSCF/Spin–orbit CI calculations for Bi+-containing model system. The estimated value of crystal ionic radius places the bismuth monocation in size near Rb+. The isomorphous substitution of Bi+ for K+, Rb+, Cs+ is possible in different crystal hosts.