DOE OSTI2020
Sc7(Mn3Ge4)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are three inequivalent Sc sites. In the first Sc site, Sc is bonded in a 7-coordinate geometry to seven Ge atoms. There are a spread of Sc–Ge bond distances ranging from 2.60–3.01 Å. In the second Sc site, Sc is bonded in a 4-coordinate geometry to four equivalent Mn and five Ge atoms. All Sc–Mn bond lengths are 2.84 Å. There are four shorter (2.87 Å) and one longer (3.25 Å) Sc–Ge bond lengths. In the third Sc site, Sc is bonded in a 7-coordinate geometry to one Mn and six Ge atoms. The Sc–Mn bond length is 2.78 Å. There are a spread of Sc–Ge bond distances ranging from 2.64–2.96 Å. There are two inequivalent Mn sites. In the first Mn site, Mn is bonded in a 11-coordinate geometry to three Sc, six Mn, and two equivalent Ge atoms. There are two shorter (2.49 Å) and four longer (2.66 Å) Mn–Mn bond lengths. Both Mn–Ge bond lengths are 2.57 Å. In the second Mn site, Mn is bonded in a 5-coordinate geometry to two equivalent Mn and five Ge atoms. There are a spread of Mn–Ge bond distances ranging from 2.54–2.84 Å. There are four inequivalent Ge sites. In the first Ge site, Ge is bonded in a 10-coordinate geometry to six Sc, three Mn, and one Ge atom. The Ge–Ge bond length is 2.74 Å. In the second Ge site, Ge is bonded in a 9-coordinate geometry to nine Sc atoms. In the third Ge site, Ge is bonded in a 8-coordinate geometry to four equivalent Sc and four equivalent Mn atoms. In the fourth Ge site, Ge is bonded in a 9-coordinate geometry to four Sc, four equivalent Mn, and one Ge atom. The Ge–Ge bond length is 2.50 Å.