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SrGe crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Sr is bonded in a 7-coordinate geometry to seven equivalent Ge atoms. There are a spread of Sr–Ge bond distances ranging from 3.30–3.40 Å. Ge is bonded in a 9-coordinate geometry to seven equivalent Sr and two equivalent Ge atoms. Both Ge–Ge bond lengths are 2.66 Å.
SrGe(HO2)2 crystallizes in the tetragonal I-42d space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.61 Å) and four longer (2.73 Å) Sr–O bond lengths. Ge4+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Ge–O bond lengths are 1.78 Å. H1+ is bonded in a linear geometry to two equivalent O2- atoms. Both H–O bond lengths are 1.22 Å. O2- is bonded in a 2-coordinate geometry to two equivalent Sr2+, one Ge4+, and one H1+ atom.
SrGe(PO4)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.61–2.77 Å. Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share corners with six equivalent PO4 tetrahedra. There are a spread of Ge–O bond distances ranging from 1.85–1.93 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent GeO6 octahedra. The corner-sharing octahedra tilt angles range from 36–49°. There are a spread of P–O bond distances ranging from 1.52–1.58 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+, one Ge4+, and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+, one Ge4+, and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Ge4+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Sr2+ and one P5+ atom.
SrGe(PO4)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Sr2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Sr–O bond distances ranging from 2.63–3.06 Å. Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share corners with six equivalent PO4 tetrahedra. There is two shorter (1.85 Å) and four longer (1.92 Å) Ge–O bond length. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent GeO6 octahedra. The corner-sharing octahedra tilt angles range from 38–46°. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Ge4+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Sr2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+, one Ge4+, and one P5+ atom.