Interactions of H 2 O molecules in ice I. The dipole moment of an H 2 O molecule in ice

The dipole moment of an H 2 O molecule in ice is greater than the moment of an isolated H 2 O molecule, 1·84 D, owing to the electric fields of neighbouring molecules. The magnitude and direction of the field arising from the nearest 85 neighbours is computed here by representing each molecule as a series of electric multipoles. It is found that the field has the direction of the dipole moment of the central molecule and is sufficiently strong to increase its total dipole moment to about 2·60 D.