Abstract: All possible geometries of hypervalent lithium-sodium combined oxides OLi_n Na₂( n =1—4) and OLi₂Na species were determined by B3LYP-DFTmethod with 6-31G^* basis set, and the frequency calculations were done on their optimized geometries. The global minima of OLi₂Na and OLi_n Na₂( n =1—3) species were all calculated to be C_2v structures, and the OLi₄Na₂ species adopts D_2d configuration as its most stable geometry. The global minima of them were calculated to be thermodynamically stable. To dissociate one Li atom, the energies of 212.25432, 68.49208 and 245.55896 kJ/mol are needed for OLi_n Na₂( n =2, 3, 4) molecules, respectively.

Key words: Hypervalent compounds, Structure and stability, Vibrational frequencies, DFT method calculation