Chemical bonding in thermodynamically labile oxyanion crystals

Crystal valence density and difference density distributions were calculated for NaNO2, NaNO3, KClO3, and NaClO4 using local density functional theory. Hybridization of the oxygen states is enhanced in compounds with lower symmetry, leading to the formation of oxygen chains in the lattice. Interaction between the oxygen and anion's central atom sublattices gives rise to electron charge maxima in the middle of the A-O bonds and to two terminal oxygen maxima. The complex character of the intraanion electron transfer and the charge transfer between the nonequivalent oxygen sublattices make these compounds susceptible to external energy effects that lead to their solid-state decomposition.