Ab initio structure and energetics of ice Ih - implications for wetting

The lattice energy of ice Ih is found to equal 0.68 eV/H$_{2}$O, in a VASP-based, GGA/PW91 optimization of a 96-molecule cell, with zero dipole moment in every hexagonal layer.\footnote{J. A. Hayward, J. R. Reimers, J. Chem. Phys. \textbf{106}, 1518(1997).} This result agrees closely with Hamann's value, obtained for a small, proton-ordered, and thus polarized unit cell.\footnote{D. R. Hamann, private communication. See, P. J. Feibelman, Science \textbf{295}, 99(2002), ref. 19.} Slight inhomogeneous broadening of the O-H stretch peak is estimated, based on the computed O-O distance distribution. Implications regarding wetting-layer formation will be discussed.