Ab initio MINDO/3, MNDO an DV-Xa quantum chem. calcns. were used to study several mol. and ionic azides and their corresponding chlorides. The electronegativities of mol. azides were smaller than those of the chlorides, but larger than those of the ionic azides. The localized and delocalized MO were calculated The differences in electronegativities in the ionic and nonionic azides were attributed to the difference and bonding types.

Key words: AZIDE, CHLORIDE, ELECTRONIC STRUCTURE, AB INITIO CALCULATION, ELECTRONEGATIVITY, MOLECULAR ORBITALS CALCULATIONS