19F NMR chemical shielding for metal fluorides MF2 (M=Zn, Cd, Pb), MF3 (M=Al, Ga, In) and SnF4

The 19F NMR chemical shieldings of MF2 (M=Zn, Cd, Pb), MF3 (M=Al, Ga, In), and SnF4 were studied by the GIAO-B3LYP method. The aug-cc-pVTZ basis set was used for the inspected fluorine atom, and LanL2DZ for the remaining fluorine atoms. The 3-21G(2d) basis set was utilized for the Al atom, and CRENBL and/or DZVP for the other metal atoms. When appropriate cluster models were employed, the theoretical shieldings agree well with experimental ones. The relativistic and electron correlation effects have greater influence on the calculated results of fluorides containing heavy or transition metal atoms.