The first electronic-band calculation for VSi2, the phase produced by the interface reaction between silicon and vanadium, has been performed using a linear combination of atomic orbitals approach in the extended Ḧckel approximation. The A 15 compound, V3Si, also has been investigated. The chemical bond in both compounds is found to be determined mainly by the p-d (Si-V) interaction. The d-d (V-V) interaction is also important in determining the physical properties of the compound. These interactions increase in strength with the metal concentration. The small charge transfer found in these compounds indicates a metallic bond picture. These results are used to interpret spectroscopic measurements of ultraviolet and synchrotron-radiation photoemission. © 1982 The American Physical Society.