Why does periclase have a much higher melting point than halite despite having a similar structure?

Periclase (MgO) and halite (NaCl) both crystallize in the same isometric structure type, where each cation and anion is in octahedral coordination with six neighbors. However, periclase has a significantly higher melting point because of the strength of the ionic bonds holding its crystal lattice together.123

The strength of an ionic bond, and consequently the melting point of an ionic crystal, depends heavily on the magnitude of the electrostatic charges of the ions involved. In halite, the structure is composed of monovalent ions ($N{a}^{+}$ and $C{l}^{-}$), which carry a charge of $\pm 1$. In contrast, periclase is composed of divalent ions ($M{g}^{2+}$ and $O^{2-}$), which carry a charge of $\pm 2$.314

According to the principles of electrostatic attraction, the force between ions increases with the magnitude of their charges. Because the ions in periclase possess higher charges than those in halite, the electrostatic attraction within the periclase lattice is much stronger, requiring significantly more thermal energy to break the bonds and melt the crystal.23