EN
The electronic structures of fluoroperovskite KMgF_{3}, hydridoperovskite KMgH_{3} and the dihydrido-fluoro derivated KΜgH_{2}F have been investigated. The energy bands, density of electronic states and partial wave analysis of the density of electronic states have been determined by means of the non-self-consistent augmented plane wave method with the von Barth-Hedin parametrization for the exchange-correlation term. Our results indicate that all three compounds are ionic insulators. Replacing the hydrogen atom by fluorine atom leads to increasing in the energy gap.