title: U4O9: atoms in general sites giving the hkl extinctions of special sites.
abstract: In U4O9, most of the atoms are in general 48-fold [48(e)] sites of the space group I43d and yet the hkl reflections obey the extinction rules for atoms occupying special 12-fold [12(b)] sites. An explanation is given for this effect, which can be generalized to any space group.
authors.affiliation: Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research,141980 Dubna, Moscow Region, Russia.
authors.forename: N C
authors.initials: NC
authors.lastname: Popa
authors.forename: B T M
authors.initials: BT
authors.lastname: Willis