Quantum-chemical investigation of the silicon and carbon coordination bond in their isostructural compounds

Ab initio calculations within the minimal basis set of STO -4LGTO have been carried out on molecules of type H₃MX (M = Si, C; X = H, NH₂, OH, F). The influence of the MH₃-group inversion on the electronic structure of these compounds has been investigated and illustrated by MO electron density maps. The ability of the central atom to form an additional bond has been estimated with the help of calculations on the complexes of these molecules with the hydrogen negative ion. The complexes of type H₄SiX]^? have been found to be more stable than their unbonded components. The H₄CX]^? complex formation has not proved to be advantageous.