Data items in the GEOM and related (GEOM_ANGLE,
               GEOM_BOND, GEOM_CONTACT, GEOM_HBOND and GEOM_TORSION)
               categories record details about the molecular and crystal
               geometry, as calculated from the contents of the ATOM, CELL,
               and SYMMETRY data.

               Geometry data are therefore redundant, in that they can be
               calculated from other more fundamental quantities in the data
               block. They serve, however, the dual purpose of providing a
               check on the correctness of both sets of data, and of enabling
               the most important geometric data to be identified for
               publication by setting the appropriate publication flag.