Additionally, our analysis identifies the interesting candidate 𝐵𝑎 3 𝐴𝑙𝑂 4 , which derives from the original compound 𝐵𝑎 3 𝐴𝑙𝑂 4 𝐻. It has similar composition ratio, component elements and chemistry to 𝐶𝑎 12 𝐴𝑙 14 𝑂 32the first electride stable at room temperature. 𝐵𝑎 3 𝐴𝑙𝑂 4 is orthorhombic with the space group Pnma (No. 62) and is shown alongside 𝐶𝑎 12 𝐴𝑙 14 𝑂 32 in Figure . Bath cases exhibit similar 0D electride behaviour. We calculate the band structures of 𝐵𝑎 3 𝐴𝑙𝑂 4 and 𝐵𝑎 3 𝐴𝑙𝑂 4 𝐻, as shown in Figure . As we can see, the band gap in 𝐵𝑎 3 𝐴𝑙𝑂 4 𝐻 disappears in 𝐵𝑎 3 𝐴𝑙𝑂 4 with the removal of hydrogen atoms, just as is observed for other electrides upon removal of an anion species, e.g. H in of Sr 3 CrN 3 and O in 𝐶𝑎 12 𝐴𝑙 14 𝑂 32 . The bands also show the strongly dispersive Please do not adjust margins Please do not adjust margins nature around the Fermi level, similar to the electronic band structures calculated for other electrides. A few other candidates that are worthy of note are 𝑁𝑏 2 𝑃 3 𝑂 12 , which is the only instance of niobium present in an electride in our candidate set and to the knowledge of the authors the first predicted niobium containing electride (see Figure of the SI for the chemical structure and electron density plot for this material). This compound contains no strongly electron positive species only the niobium which is of course a transition metal element capable of multiple oxidation states. GdS and GdTe are also worthy of further exploration as isostructural, cubic 0D gadolinium electrides, given that Gd 2 C is a known electride that exhibits ferromagnetism above room temperature. The structure and electron density for these compounds is shown in Figure .