Citation: Sobolev, B.P.; Golubev, A.M.; Otroshchenko, L.P.; Herrero, P.; Ryzhova, E.A.; Zakalyukin, R.M.; Molchanov, V.N. (2003). Ba1-x Rx F2+x phases (R = Gd-Lu) with distorted fluotite-type structures - products of crystallization of incongruent melts in the Ba F2 - R F3 systems (R = Gd-Lu). III. Defect Ba0.75 Lu0.25 F2.25 structure. A new (Lu8 (Ba6 F71)) supercluster of defects. Kristallografiya, 48, pp. 1012-1020.