Ca3(NbGa)5O12 cubic garnets. Nb, Ga and vacancies share the 16a (octahedral) and 24d (tetrahedral) sites of the garnet structure. Further Na shares with Ca the 24c (dodecahedral) and Li fills the tetrahedral vacancies in 24d sites.
Tetragonal NaM(NO4)2 (M= Y,La,Gd,Lu,Bi and N= Mo,W). 2d and 2b crystal sites are shared by Na and M cations. Yb and other laser active Ln also enter in these same sites.
Monoclinic, In-modified KY(WO4)2. In, Y and the laser Ln share the same 4e Wickoff crystal site.
Monoclinic, Li3Ln3Ba2(MoO4)8. 8f Wickoff site is shared by Li and Ln.