Fig. 4: TKE responses of different materials.

a The TKE responses of diamond (top-red) and ethanol (middle-green) exhibit similar double-peak structures with a time interval of 0.13ps. The simulated electronic responses of diamond and ethanol are shown as dark grey and light grey lines, respectively. In comparison, the TKE response of liquid water (bottom) comprises a broadened double-peak structure with a time interval of 0.17ps and an obvious negative component. b The TKE responses of liquid water and heavy water are demonstrated for comparison