These graphics show the regular arrangement of water molecules in ice.
The configuration is maintained by hydrogen bonds between hydrogen and oxygen atoms on neighbouring water molecules.
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hide H bonds.
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In ice the maximum number of 4 hydrogen bonds per water molecule is reached.
This locks the water molecules into "sheets" with a
hexagonal structure and spaces them out so that ice has a lower density than water, and ice floats on water, giving an insulating layer which enables life to exist in water beneath.
The first view shows
28 water molecules in ice - forming 2 layers.
The hexagonal motif repeats when seen
side on.
The arrangement of water molecules is more obvious in this
larger model, showing
432 H20 molecules.
H bonds
on /
off
When rotated,
this structure reveals its regularity, turned through
60 °
/
120 ° about the y axis, and
back again .
Rotation of
90 ° about the y axis shows the layers from the edge.
Rotation about the x axis shows repeats at 90 ° intervals:
90 °
/
180 °