This difference can be attributed to the M cation in A 14 M X 11 . In Yb 14 M Sb 11 compounds, the conduction bands are separated into those that are purely of (Sb 3 ) 7-character (i.e., the σ * bands) and those that are higher in energy. The latter group of conduction bands have partial M character, meaning that the bands will be lower in energy in Yb 14 AlSb 11 than in Yb 14 MgSb 11 due to the higher electronegativity of Al. We also do not expect the absolute energies of the σ * bands to differ significantly between the two compounds, as the (Sb 3 ) 7- maximum (VBM) and the s-orbitals contributing to the bands located ∼ 8 eV below the Fermi energy (Figure ). Similar to the σ * conduction bands, we can distinguish features of the valence bands between Yb 14 AlSb 11 and Yb 14 MgSb 11 . Notably, an isolated set of peaks appears in the DOS ∼ 5 eV below the Fermi energy in Yb 14 AlSb 11 that is not present in Yb 14 MgSb 11 . There are four bands that contribute to the peaks (the a 1 bands), which are mainly comprised of Al-s and Sb-p atomic orbitals in Yb 14 AlSb 11 , as evidenced by both the partial density of states (Figure ) and the orbital-decomposed band structure (Figure ). Moreover, the charge density distribution of the a 1 bands (Figure ) suggests that the states are of bonding character. While the a 1 bands are isolated from the rest of the valence bands in Yb 14 AlSb 11 , orbital contributions from Mg indicates that the a 1 bands are merged into the other valence bands in Yb 14 MgSb 11 (Figure ). The difference in the electronic structures can again be attributed to the higher electronegativity of Al, which lowers the energies of the a 1 bands in Yb 14 AlSb 11 relative to those in Yb 14 MgSb 11 .