Y. Zhang Iono-covalent theory applications (23)
American Huilin Institute http://www.amhuilin.com/
Reguera et al.  have measured the Mössbauer spectra of 29 nitroprussides and correlatered the parameters d and Δ with the Zhang's polarizing power Z/rk2 . And found that in isoelectronic sequences of cation in the periodic chart, such as Li+ ,Be2+; Mn2+,Fe3+, both d and Δ decrease with increase in Z/rk2 (Zhang 1982b).
 Reguera, E., Bertran, J. F., Miranda, J.,Portilla, C., J. Radioanal. Nucl. Chem., letters，165 (3)（1992）191-201.
 Y. Zhang, Inorg. Chem., 21(1982) 3889