Interpretation of the 119Sn Mossbauer parameters

The variations of the Sn-119 Mossbauer isomer shift delta are interpreted for tin compounds from a semi-empirical tight-binding calculation of the electronic density at the nucleus rho(0). A molecular model is proposed in order to relate the variations of rho(0) for the Sn(IV) chalcogenides to the changes in the Sn environment. The variations of the experimental values of the quadrupole splitting delta are linearly correlated to the values of the electric field gradients (EFG) calculated by the full-potential linearized-augmented-plane-wave (FP-LAPW) method. The value of the Sn-119 nuclear quadrupole moment is found to be \Q\ = 10.5 +/- 0.2 fm(2). Finally, the relation between the EFG and the Sn environment is discussed for SnO.