We will use cif to cell to generate cell files from cif files. Cif files can be obtained from the ICSD (inorganic crystals) or the CSD (molecular crystals).

MgO Examine the file http://www.wannier.org/files/MgO.cif. Look at the crystal structure with jmol or magresview (drag and drop the file onto the magresview window). You will see a cubic face-centre cubic cell. How many atoms in the cell?

Use cif2cell to convert this cif file to a cell file.

cif2cell MgO.cif --program=castep -o MgO.cell

Look at the cell file. How many atoms in the cell? View this will jmol or magresview. Do you understand what cif2cell has done?

Molecular Tweezers Examine the file http://www.wannier.org/files/GUQHUV.cif

cif2cell -p castep --export-cif-labels GUQHUV.cif -o GUQHUV.cell

Look at the cell file. Note the labeling in the cif file has been added in the label field.

Do a dryrun calculation and examine the castep file. castep -d GUQHUV