Charge transfer caused anomalies of physical properties of

Persistent efforts have been devoted to unraveling the fundamental mechanism behind superconductivity. In the pursuit of novel unconventional superconductors, layered transition metal compounds have emerged as promising candidates. In this work, transmission electron microscopy, electron energy loss spectroscopy (EELS), and first-principles calculations are used to investigate the underlying causes of the anomalies of the susceptibility and resistivity of KV2Se2O. No evidence of either long-range or short-range ordered structural phase transition related to CDW is observed. However, our findings reveal a variation in the electronic configuration of vanadium occurring at low temperatures, which is supported by EELS spectra and Bader charge analysis. The change in electronic configuration may elucidate the anomalies of physical properties.