The chemical environmental factor was defined with the covalency and polarizability of a bond.Since the factor can effectively describe the change trends of the chemical shifts in the above spectra,the bond nature of the chemical shifts was revealed.The clear quantitative relations between the environmental factors and M(o)ssbauer isomer shift of various ions such as 57Fe and 119Sn were obtained.We can predict the isomer shifts in all kinds of complex crystals by using this theory.On the one hand,these relations will be useful for us to analyze M(o)ssbauer spectroscopy,or otherwise,the experiments in M(o)ssbauer spectroscopy can verify validity of the chemical bond dielectric theory for the complex crystals.In this paper,a calculation method which was more suitable to calculate the chemical bond parameters of layered crystals was proposed based on the dielectric theory of complex crystals.Using the method,we calculated the chemical bond parameters and M(o)ssbauer isomer shift values of lanthanide layered superconductors and a few of ferric compounds.Besides,the chemical bond parameters and refractive index values of other crystals with different structures have also been calculated.The quantitative relationship between isomer shift,refractive index and chemical bond parameters were established.The calculated results indicated that the change of crystal parameters and bond length will alter the covalency of chemical bond and peripheral electron density of Fe2+ nuclear,which in turn leads to the change of the isomer shift and refractive index.The good agreement between the calculated results and available experimental data proved the accuracy and universality of the theory.