Hydrogen bonds between water molecules: Thermal expansivity of ice and water

The free energy components of two low pressure crystalline ices and an amorphous form of water are calculated over a wide range of temperatures. The Gibbs free energy at a given temperature is minimized with respect to volume of a system. This enables us to evaluate a thermal expansivity at fixed temperature and pressure from only intermolecular interaction potential. The negative thermal expansivity at low temperature is obtained for both crystalline ices and an amorphous form, which arises from the bending motion of hydrogen bonded molecules. (C) 2001 Elsevier Science B.V. All rights reserved.