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Polycrystalline CuMo1−xWxO4 solid solutions were studied by resonant X-ray emission spectroscopy (RXES) at the W L3-edge to follow a variation of tungsten local atomic and electronic structures across thermochromic phase transition as function sample composition temperature. The experimental results interpreted using ab initio calculations. crystal-field splitting parameter Δ for 5d(W)-states was obtained from analysis RXES plane used evaluate coordination atoms. Temperature-dependent measurements successfully employed determine hysteretic behaviour structural between α γ phases in on cooling heating, even low (x<0.10) content. It found that ions have octahedral x>0.15 whole temperature range (90-420 K), whereas their changes tetrahedral upon smaller (x≤0.15) Nevertheless, some amount co-exists environment room x<0.15. correlate well with color change these solutions.