Crystal structure of Dy${}_{11}$Ge${}_{4.33}$In${}_{5.67}$ and Tm${}_{11}$Ge${}_4$In${}_6$ from X-ray single-crystal and powder data

Single crystals of Dy${}_{11}$Ge${}_{4.33}$In${}_{5.67}$ were grown from a sample of the starting composition Dy${}_{55}$Ge${}_{20}$In${}_{25}$ by arc-melting and subsequent annealing. Dy${}_{11}$Ge${}_{4.33}$In${}_{5.67}$ crystallizes with the Sm${}_{11}$Ge${}_4$In${}_6$-type structure, space group I4/mmm, which was refined from single-crystal X-ray diffractometer data: a = 11.4329(16), c = 16.168(3) Å, wR2 = 0.0341, 927 F${}^2$ values and 42 refined parameters. The isotypic compound Tm${}_{11}$Ge${}_4$In${}_6$ was characterized by X-ray powder diffraction: a = 11.262(2), c = 15.979(3) Å, R${}_{Bragg}$ = 3.53%. The Sm${}_{11}$Ge${}_4$In${}_6$-type structure is a coloring variant of the Ho${}_{11}$Ge${}_{10}$ type, realized through germanium-indium ordering. The p-element substructure has four crystallographically independent sites: isolated germanium atoms (Ge${}^{4-}$ Zintl anions), In${}_4$ squares and In/Ge-In/Ge dumb-bells with pronounced Ge/In mixing.