Figure 1

(Color online) (a) Measured oxygen $K$-edge soft x-ray spectra, calculated x-ray spectra, and calculated density of states for BeO. The XES excitation energy, at 540.8 eV, is marked by an arrow at the corresponding location in the XAS. The Fermi level $\left(E_{\text{F}}\right)$ is denoted by a vertical line. The second derivative of the measured x-ray spectra is plotted at the bottom with the band gap ${\Delta }_{\text{g}}$ and the valence-band width ${\Delta }_{\text{VB}}$ labeled. Note that the scale for the DOS varies; for the total DOS it is in (states/eV/unit cell) and for oxygen it is in (states/eV/atom). Both occupied and unoccupied ground-state DOSs are displayed here, only the calculated XAS makes use of the core-hole calculation. (b) Measured oxygen $K$-edge soft x-ray spectra, calculated x-ray spectra, and calculated density of states for MgO. (c) Measured oxygen $K$-edge soft x-ray spectra, calculated x-ray spectra, and calculated density of states for CaO. (d) Measured oxygen $K$-edge soft x-ray spectra, calculated x-ray spectra, and calculated density of states for SrO. (e) Measured oxygen $K$-edge soft x-ray spectra, calculated x-ray spectra, and calculated density of states for BaO.Reuse & Permissions

Figure 2

(Color online) (a) Measured oxygen $K$-edge soft x-ray spectra, calculated x-ray spectra, and calculated density of states for ZnO. This figure has the same format as Fig. 1a. (b) Measured oxygen $K$-edge soft x-ray spectra, calculated x-ray spectra, and calculated density of states for CdO. (c) Measured oxygen $K$-edge soft x-ray spectra, calculated x-ray spectra, and calculated density of states for HgO.Reuse & Permissions

Figure 3

(Color online) The left-hand side shows the calculated band gap $G_{\text{c}}$ plotted with respect to the measured gap ${\Delta }_{\text{g}}$. The right-hand side shows the width of the calculated valence band $W_{\text{VB}}$ plotted with respect to the width of the measured XES ${\Delta }_{\text{VB}}$. In both plots the gray line shows the ideal relationship if the calculations perfectly matched the measurement, and the dotted black line shows the best linear fit through the data.Reuse & Permissions

Figure 4

(Color online) (a) Calculated oxygen $2p$ and beryllium $2s$ and $2p$ valence-band DOS for BeO. Note the oxygen DOS is scaled differently than the metal DOS. (b) Calculated oxygen and magnesium DOS for MgO. (c) Calculated oxygen and calcium DOS for CaO. (d) Calculated oxygen and strontium DOS for SrO. This figure has the same format as (a). (e) Calculated oxygen and barium DOS for BaO.Reuse & Permissions

Figure 5

(Color online) The energy of the center point (or “centre of gravity”) of the cation valence $ns$, $np$, and $nd/\left(n-1\right)d$ states for the alkaline-earth oxides.Reuse & Permissions

Figure 6

(Color online) (a) Calculated oxygen $2p$ and zinc $4s$, $4p$, and $3d$ valence-band DOS for ZnO. Note the oxygen DOS is scaled differently than the metal DOS. The $3d$ states at feature $\mathbf{c}$ have been scaled by a factor of 0.1, since otherwise the cation states near the Fermi level would be too small to see. (b) Calculated oxygen and cadmium DOS for CdO. (c) Calculated oxygen and mercury DOS for HgO.Reuse & Permissions

Figure 7

(Color online) The energy of the center point (or centre of gravity) of the cation valence $ns$, $np$, and $nd/\left(n-1\right)d$ states for the post-transition-metal oxides.Reuse & Permissions