Hydration of OH radical in high temperature water

►Simulation study on hydration and hydrogen-bonding of OH in high temperature water is presented. ►For the first time flexible models of solution components are employed. ►Non-meaningless role of short-range interaction of hydrogen atoms is indicated. ►The number of H-bonds resulting from different definitions is provided and compared. ►Seeking mechanism in liquid phase and structure-making in low-density supercritical water are proposed.