Resources written by Chas McCaw for sixth form chemistry teaching and beyond.
General interest:
Graphite Buckminsterfullerene Ice White phosphorus Benzene Cyclohexane AdamantaneCubic:
Sodium Caesium chloride Polonium Copper Halite Fluorite Antifluorite Zinc blende DiamondNon-cubic:
Hexagonal:
Magnesium WurtziteTetragonal:
RutileTrigonal:
α-quartzTriclinic:
Copper(II) sulfateOrthorhombic:
α-SulfurMonoclinic:
β-SulfurThe image to the left shows two unit cells side-by-side. Notice that the chloride ion in the centre of the structure occupies the centre of a unit cell that is equivalent to the one seen on earlier pages, except the chloride ions are now occupying the positions that were once occupied by sodium ions, and vice versa. This shows that a mere displacement of the halite unit cell by half a unit cell length along one of its cartesian axes gives an equivalent cell around the counter ion. A black octahedral wireframe is drawn around the central chloride ion to emphasise that the geometry around the chloride ion is equivalent to the sodium ion's geometry.
Go to page 7 to consider a polyhedral representation of halite.