The organic molecule below,

crystallizes in the triclinic space group . There is only one symmetry element in this space group - a center of symmetry at the origin of the unit cell. The center of symmetry "inverts" each atom through the origin to produce an identical symmetry-related atom with co-ordinates -x, -y, -z (click on "center").

This molecule, however, is in a neighboring cell. To move it into this unit cell, translate it by 1 unit cell length in each cell direction (click on "Translate 1 1 1):

The two molecules displayed in the unit cell are related by a center of symmetry at ½, ½, ½.