A liquid water model: Density variation from supercooled to superheated states, prediction of H-bonds, and temperature limits

The expressions for density and fraction of H-bonding H atoms are derived a nd applied from supercooled to superheated states of liquid water (H2O). Th e anomalous density variation (around 4 degreesC) with temperature is expla ined solely on the basis of H-bonding and non-H-bonding (NHB) H atoms in th e liquid. Interesting structural changes are postulated as the temperature of liquid water increases from a very low to a very high value. The limits of supercooling and superheating temperatures are calculated to be around 1 80 and 980 K, respectively, at 1 atm pressure.