Predicting metal-to-metal charge transfer in closed-shell transition metal oxides doped with Bi3+ or Pb2+

► Incorporating Bi3+ or Pb2+ ions in d0 transition metal oxides generates MMCT transitions in the NUV. ► The MMCT transitions are predictable from the structural properties of the host lattices. ► The Eu3+ or Pr3+ luminescence can be sensitized by NUV excitation in the MMCT bands. ► Predicting MMCT transitions in Bi3+; Ln3+ codoped oxides allows the design of down-converters.