In liquid water each
molecule is hydrogen bonded to approximately 3.4 other water molecules. In ice
each each molecule is hydrogen bonded to 4 other molecules.
the two structures below. Notice the empty spaces within the ice structure. Click
on the images to view larger gif files.
click here click
To view these molecules using a Java Applet click
In ice Ih, each water forms four hydrogen bonds
with O---O distances of 2.76 Angstroms to the nearest oxygen neighbor. The O-O-O
angles are 109 degrees, typical of a tetrahedrally coordinated lattice structure.
The density of ice Ih is 0.931 gm/cubic cm. This compares with
a density of 1.00 gm/cubic cm. for water.