Data items in the IHM_GEOMETRIC_OBJECT_HALF_TORUS category records the parameters of half-torus that represents a membrane.
loop_ _ihm_geometric_object_half_torus.object_id _ihm_geometric_object_half_torus.thickness_th _ihm_geometric_object_half_torus.section 1 1.0 inner 2 2.0 inner # ... abbreviated ...