Ab initio calculations of 19FNMR chemical shielding for alkali-metal fluorides1Projects 19605004, 29892166 supported by National Natural Science Foundation of China, Natural Science Foundation of Fujian Province.1

[M 6 F] 5+ clusters were chosen to calculate the 19 F NMR chemical shielding for solid state alkali-metal fluorides MF (M=Li, Na, K, Rb) using gauge-independent atomic orbitals (GIAO) at Hartree–Fock (HF) and density functional theory (DFT) levels, respectively. The results agree with those measured experimentally, in particular when the relative deviations within the same series are considered. Our results reveal that the variation of chemical shielding from LiF to RbF correlates well with a combined effect from the lattice factor R −2 and the valency factor Q + Q − .