<p>Cu(I)-containing oxide semiconductors containing early transition-metal cations have been of growing interest as small bandgap semiconductors. Though, their lack of thermodynamic stability has slowed the progress of their synthetic discovery. Two new Cu(I)-molybdovanadates and one new Cu(I)-tungstovanadate have been discovered in high temperature reactions and their structures characterized using single crystal X-ray diffraction. Their chemical compositions are given by CuVMoO<sub>6</sub>, Cu<sub>1.51(1)</sub>V<sub>3.57(1)</sub>Mo<sub>0.43(1)</sub>O<sub>11</sub> and Cu<sub>1.59(1)</sub>V<sub>3.52(1)</sub>W<sub>0.48(1)</sub>O<sub>11</sub>. The latter two structures possess a Cu site with ~25% occupancy, whereas all structures show a statistical disorder of V/Mo or V/W cations over equivalent crystallographic sites. Using a supercell approach, density functional theory calculations have been performed to understand their thermodynamic stabilities and their relationships to their band structures and densities-of-states (DOS). Results of the calculations showed lower total energies are attained when the partially-filled Cu sites are oxygen-bridged to the V atoms rather than the Mo/W atoms. Results of their DOS and band structures were also found to provide deeper insights into their physical properties as ternary, Cu(I)-containing oxides. </p>
