Reply to “Comment on ‘Charge order inFe2OBO3: AnLSDA+Ustudy’”

The experimental difficulties of observing ${\mathrm{Fe}}^{2+}∕{\mathrm{Fe}}^{3+}$ charge order in ${\mathrm{Fe}}_2{\mathrm{OBO}}_3$ and ${\mathrm{Fe}}_3{\mathrm{O}}_4$ are different and are considered separately. Charge order in ${\mathrm{Fe}}_3{\mathrm{O}}_4$ has a complex arrangement but is long-range coherent, as evidenced by a recent structure determination and two resonant x-ray diffraction studies. Long-range charge order has not been observed crystallographically in ${\mathrm{Fe}}_2{\mathrm{OBO}}_3$, although there is substantial indirect evidence for ${\mathrm{Fe}}^{2+}∕{\mathrm{Fe}}^{3+}$ ordering over shorter distances. Further support is provided by $\mathrm{LSDA}+\mathrm{U}$ calculations on a doubled unit cell of ${\mathrm{Fe}}_2{\mathrm{OBO}}_3$, which shows a charge separation similar to that in ${\mathrm{Fe}}_3{\mathrm{O}}_4$, with a large $t_{2\mathrm{g}}$ subshell occupancy difference that is partially screened by $\mathrm{Fe}\text{−}\mathrm{O}$ covalency.