Electronic states of the molten chlorides of alkali metals, magnesium and zinc have been investigated using DV-Xα molecular orbital calculation. Bond order and ionisity were utilized to clarify charge distributions between metal ions and chlorine ions. The results are as follows:
(1) Within the molten chlorides of alkali metals, as the atomic number increases, the ionisity becomes higher and the bond order becomes lower, that is, the strength of the covalent bond becomes lower.
(2) The molten chlorides of magnesium and zinc metals are higher in the strength of covalent bond than the molten chlorides of alkali metals. This is probably the reason for the formation of the complex ions of the molten chlorides of magnesium and zinc.
(3) It was found that the molten chlorides with higher bond order values showed the lower equivalent conductivities.
Thus, it is found that the molecular orbital calculation is very useful in investigating the electronic states of molten salts.
