Red-shifted near-infrared emissions in ${\mathrm{Cr}}^{3+}$-activated oxides at high concentrations are commonly attributed to ${\mathrm{Cr}}^{3+}\text{−}{\mathrm{Cr}}^{3+}$ ion pairs, yet whether these redshifts arise from exchange-coupled pairs or from locally perturbed isolated ions remains unclear. To address this issue, we establish a first-principles framework that quantitatively determines the ground-state exchange coupling constant $J$ and the emission redshift of the ${\mathrm{Cr}}^{3+}$ pairs in strong crystal-field environments. Our calculations reveal that face-sharing octahedral pairs can exhibit redshifts up to $\sim 0.2\mathrm{eV}$, whereas edge-sharing and corner-sharing pairs show only moderate ($<0.15\mathrm{eV}$) and small ($<0.07\mathrm{eV}$) shifts. We further find that excited-state electron-phonon coupling acts synergistically with magnetic exchange, significantly influencing both the Stokes shift and the redshift amplitude. This unified picture clarifies the microscopic origin of pair-related near-infrared emissions and provides a practical criterion for distinguishing genuine ${\mathrm{Cr}}^{3+}\text{−}{\mathrm{Cr}}^{3+}$ ion-pair centers from other luminescent defects in ${\mathrm{Cr}}^{3+}$-activated oxides.

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• Crystal defects
• Electronic structure
• Luminescence
• Insulators
• Transition metal oxides
• Density functional theory
• First-principles calculations