Vacancy ordering in Gd_1-xSe

Vacancy ordering is observed in the compound Gd0.88Se. The symmetry is reduced fromFm3m- for stoichiometric GdSe toPm3m- and the cubic cell edge is 5.7669(4)A °. The Gd occupancies become of Cu3Au type, whereas no vacancies or distortions were observed for the Se sublattice. © 1987 Academic Press, Inc. All rights reserved.