DOE OSTI2020
Ba20Hg99Zn5 crystallizes in the cubic F-43m space group. The structure is three-dimensional. there are four inequivalent Ba sites. In the first Ba site, Ba is bonded in a 12-coordinate geometry to eighteen Hg atoms. There are a spread of Ba–Hg bond distances ranging from 3.78–3.86 Å. In the second Ba site, Ba is bonded in a 1-coordinate geometry to seventeen Hg atoms. There are a spread of Ba–Hg bond distances ranging from 3.56–4.04 Å. In the third Ba site, Ba is bonded in a 1-coordinate geometry to fifteen Hg atoms. There are a spread of Ba–Hg bond distances ranging from 3.42–3.69 Å. In the fourth Ba site, Ba is bonded in a 12-coordinate geometry to sixteen Hg atoms. There are a spread of Ba–Hg bond distances ranging from 3.72–3.99 Å. There are twelve inequivalent Hg sites. In the first Hg site, Hg is bonded in a distorted single-bond geometry to three equivalent Ba, three equivalent Hg, and one Zn atom. All Hg–Hg bond lengths are 3.18 Å. The Hg–Zn bond length is 2.95 Å. In the second Hg site, Hg is bonded in a distorted trigonal planar geometry to three Ba atoms. In the third Hg site, Hg is bonded in a 7-coordinate geometry to four Ba and four Hg atoms. There are a spread of Hg–Hg bond distances ranging from 2.97–3.07 Å. In the fourth Hg site, Hg is bonded to three equivalent Ba and nine Hg atoms to form face-sharing HgBa3Hg9 cuboctahedra. There are three shorter (3.26 Å) and three longer (3.29 Å) Hg–Hg bond lengths. In the fifth Hg site, Hg is bonded in a tetrahedral geometry to four equivalent Ba atoms. In the sixth Hg site, Hg is bonded in a 9-coordinate geometry to four Ba, four Hg, and one Zn atom. There are one shorter (3.10 Å) and one longer (3.24 Å) Hg–Hg bond lengths. The Hg–Zn bond length is 3.23 Å. In the seventh Hg site, Hg is bonded in a distorted q6 geometry to three equivalent Ba and six Hg atoms. There are three shorter (3.16 Å) and three longer (3.21 Å) Hg–Hg bond lengths. In the eighth Hg site, Hg is bonded in a 2-coordinate geometry to three equivalent Ba, six Hg, and two Zn atoms. All Hg–Hg bond lengths are 3.28 Å. There are one shorter (2.69 Å) and one longer (2.80 Å) Hg–Zn bond lengths. In the ninth Hg site, Hg is bonded in a 8-coordinate geometry to four Ba, six Hg, and one Zn atom. The Hg–Zn bond length is 2.98 Å. In the tenth Hg site, Hg is bonded in a 10-coordinate geometry to two Ba and eight Hg atoms. There are two shorter (3.18 Å) and two longer (3.39 Å) Hg–Hg bond lengths. In the eleventh Hg site, Hg is bonded in a distorted single-bond geometry to three Ba, three Hg, and one Zn atom. The Hg–Zn bond length is 2.75 Å. In the twelfth Hg site, Hg is bonded in a 8-coordinate geometry to three Ba and five Hg atoms. There are one shorter (2.97 Å) and two longer (3.04 Å) Hg–Hg bond lengths. There are two inequivalent Zn sites. In the first Zn site, Zn is bonded in a body-centered cubic geometry to eight Hg atoms. In the second Zn site, Zn is bonded in a 8-coordinate geometry to eight Hg atoms.