The structures and stability of silyleniods H2SiNaX(X=F, Cl)were predicted by ab initio calculations. the STO-3G basis set was used for full geometry optimizations.the two most stable forms are suggested to be the structrues with three-membered ring and p-comlex, analogous to the similar structures previously found for silyleniod H2SiLiCl. two species σ-complex and dthe "classical"(tetrahedral)form, are also local minima on the potential energy surface, but higher in energy and unstable.

Key words: STABILITY, SODIUM COMPOUNDS, CONFIGURATION, HALOGEN, STRUCTUREIZATION, ISOMERIC COMPOUND