Charge-Transfer and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>d</mml:mi><mml:mi>d</mml:mi></mml:mrow></mml:math> excitations in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>AgF</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>

Charge-transfer insulators are the parent phase of a large group today's unconventional high-temperature superconductors. Here we study experimentally and theoretically interband excitations charge-transfer insulator silver fluoride ${\mathrm{AgF}}_{2}$, which has been proposed as an excellent analog oxocuprates. Optical conductivity resonant inelastic x-ray scattering on ${\mathrm{AgF}}_{2}$ polycrystalline sample show close similarity with that measured undoped ${\mathrm{La}}_{2}{\mathrm{CuO}}_{4}$. While former shows gap $\ensuremath{\sim}3.4$ eV, larger than in cuprate, $dd$ nearly at same energy two materials. Density functional theory exact diagonalization cluster computations multiplet spectra is more covalent spite fundamental gap. Furthermore, verge instability. The overall resemblance our data to those published previously ${\mathrm{La}}_{2}{\mathrm{CuO}}_{4}$ suggests underlying physics same, while could also benefit from proximity charge density wave ${\mathrm{BaBiO}}_{3}$. Therefore, work provides compelling support future use fluoroargentates for materials' engineering novel