Valence-electron distribution of cesium crown-ether electrides

Dye has argued that in the electride Cs(18-crown-6${)}_2$ the valence electrons are localized in interstitial regions, or traps, which are far from the cesium nuclei (forming a lattice of F centers). Golden and Tuttle (GT) have argued that this picture is incorrect, the electron distribution being located instead in the immediate vicinity of the Cs nucleus. Here we refute GT’s arguments. We also give arguments based on ab initio calculations for an electride-type molecule, which supports a picture like Dye’s versus one where the electron probability is mainly near the cesiums.