DOE OSTI2020
La6S3(OF4)2 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are twelve inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 7-coordinate geometry to two equivalent S2- and seven F1- atoms. Both La–S bond lengths are 3.03 Å. There are a spread of La–F bond distances ranging from 2.39–2.54 Å. In the second La3+ site, La3+ is bonded in a 7-coordinate geometry to two equivalent S2- and seven F1- atoms. Both La–S bond lengths are 3.02 Å. There are a spread of La–F bond distances ranging from 2.41–2.55 Å. In the third La3+ site, La3+ is bonded in a 9-coordinate geometry to two equivalent S2-, one O2-, and six F1- atoms. Both La–S bond lengths are 3.04 Å. The La–O bond length is 2.38 Å. There are a spread of La–F bond distances ranging from 2.48–2.55 Å. In the fourth La3+ site, La3+ is bonded in a 9-coordinate geometry to two equivalent S2-, one O2-, and six F1- atoms. Both La–S bond lengths are 3.05 Å. The La–O bond length is 2.42 Å. There are a spread of La–F bond distances ranging from 2.45–2.58 Å. In the fifth La3+ site, La3+ is bonded in a 9-coordinate geometry to two equivalent S2-, one O2-, and six F1- atoms. Both La–S bond lengths are 3.01 Å. The La–O bond length is 2.41 Å. There are a spread of La–F bond distances ranging from 2.50–2.53 Å. In the sixth La3+ site, La3+ is bonded in a 9-coordinate geometry to two equivalent S2-, one O2-, and six F1- atoms. Both La–S bond lengths are 3.01 Å. The La–O bond length is 2.34 Å. There are a spread of La–F bond distances ranging from 2.50–2.57 Å. In the seventh La3+ site, La3+ is bonded in a 5-coordinate geometry to four S2-, two equivalent O2-, and three F1- atoms. There are two shorter (3.11 Å) and two longer (3.19 Å) La–S bond lengths. Both La–O bond lengths are 2.48 Å. There are a spread of La–F bond distances ranging from 2.43–2.57 Å. In the eighth La3+ site, La3+ is bonded in a 5-coordinate geometry to four S2-, three O2-, and two F1- atoms. There are two shorter (3.12 Å) and two longer (3.32 Å) La–S bond lengths. There are one shorter (2.42 Å) and two longer (2.44 Å) La–O bond lengths. There are one shorter (2.49 Å) and one longer (2.59 Å) La–F bond lengths. In the ninth La3+ site, La3+ is bonded in a 5-coordinate geometry to four S2-, two equivalent O2-, and three F1- atoms. There are two shorter (3.11 Å) and two longer (3.16 Å) La–S bond lengths. Both La–O bond lengths are 2.49 Å. There are a spread of La–F bond distances ranging from 2.43–2.55 Å. In the tenth La3+ site, La3+ is bonded in a 9-coordinate geometry to four S2-, one O2-, and four F1- atoms. There are two shorter (2.98 Å) and two longer (3.19 Å) La–S bond lengths. The La–O bond length is 2.41 Å. There are a spread of La–F bond distances ranging from 2.39–2.63 Å. In the eleventh La3+ site, La3+ is bonded in a 5-coordinate geometry to four S2-, three O2-, and two F1- atoms. There are two shorter (3.16 Å) and two longer (3.29 Å) La–S bond lengths. There are one shorter (2.40 Å) and two longer (2.41 Å) La–O bond lengths. There are one shorter (2.49 Å) and one longer (2.56 Å) La–F bond lengths. In the twelfth La3+ site, La3+ is bonded in a 9-coordinate geometry to four S2-, one O2-, and four F1- atoms. There are two shorter (3.03 Å) and two longer (3.13 Å) La–S bond lengths. The La–O bond length is 2.41 Å. There are a spread of La–F bond distances ranging from 2.38–2.64 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded in a 8-coordinate geometry to six La3+, three O2-, and seven F1- atoms. There are two shorter (3.34 Å) and one longer (3.53 Å) S–O bond lengths. There are a spread of S–F bond distances ranging from 3.13–3.45 Å. In the second S2- site, S2- is bonded in a 8-coordinate geometry to six La3+, two equivalent O2-, and eight F1- atoms. Both S–O bond lengths are 3.31 Å. There are a spread of S–F bond distances ranging from 3.13–3.49 Å. In the third S2- site, S2- is bonded in a 6-coordinate geometry to six La3+, three O2-, and seven F1- atoms. There are two shorter (3.29 Å) and one longer (3.41 Å) S–O bond lengths. There are a spread of S–F bond distances ranging from 3.12–3.41 Å. In the fourth S2- site, S2- is bonded in a 8-coordinate geometry to six La3+, four O2-, and six F1- atoms. There are a spread of S–O bond distances ranging from 3.30–3.50 Å. There are a spread of S–F bond distances ranging from 3.16–3.43 Å. In the fifth S2- site, S2- is bonded in a 8-coordinate geometry to six La3+, two O2-, and eight F1- atoms. There are one shorter (3.43 Å) and one longer (3.45 Å) S–O bond lengths. There are a spread of S–F bond distances ranging from 3.18–3.27 Å. In the sixth S2- site, S2- is bonded in a 6-coordinate geometry to six La3+, two O2-, and eight F1- atoms. There are one shorter (3.38 Å) and one longer (3.43 Å) S–O bond lengths. There are a spread of S–F bond distances ranging from 3.21–3.29 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four La3+ and four S2- atoms to form OLa4S4 tetrahedra that share corners with four OLa4S4 tetrahedra, corners with seven FLa4S3 tetrahedra, an edgeedge with one FLa4S3 tetrahedra, edges with two equivalent OLa4S4 tetrahedra, faces with two equivalent OLa4S4 tetrahedra, and faces with three FLa4S3 tetrahedra. In the second O2- site, O2- is bonded to four La3+ and four S2- atoms to form OLa4S4 tetrahedra that share corners with four OLa4S4 tetrahedra, corners with seven FLa4S3 tetrahedra, an edgeedge with one FLa4S3 tetrahedra, edges with two equivalent OLa4S4 tetrahedra, and faces with five FLa4S4 tetrahedra. In the third O2- site, O2- is bonded to four La3+ and four S2- atoms to form OLa4S4 tetrahedra that share corners with four OLa4S4 tetrahedra, corners with seven FLa4S3 tetrahedra, an edgeedge with one FLa4S3 tetrahedra, edges with two equivalent OLa4S4 tetrahedra, and faces with five FLa4S3 tetrahedra. In the fourth O2- site, O2- is bonded to four La3+ and four S2- atoms to form distorted OLa4S4 tetrahedra that share corners with two OLa4S4 tetrahedra, corners with nine FLa4S3 tetrahedra, an edgeedge with one FLa4S3 tetrahedra, edges with two equivalent OLa4S4 tetrahedra, faces with two equivalent OLa4S4 tetrahedra, and faces with three FLa4S3 tetrahedra. There are sixteen inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to three La3+ and one S2- atom. In the second F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to three La3+ and one S2- atom. In the third F1- site, F1- is bonded in a trigonal non-coplanar geometry to three La3+ and one S2- atom. In the fourth F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to three La3+ and one S2- atom. In the fifth F1- site, F1- is bonded in a trigonal non-coplanar geometry to three La3+ and one S2- atom. In the sixth F1- site, F1- is bonded in a trigonal non-coplanar geometry to three La3+ and one S2- atom. In the seventh F1- site, F1- is bonded to four La3+ and three S2- atoms to form distorted FLa4S3 tetrahedra that share corners with two equivalent FLa4S4 tetrahedra, corners with three OLa4S4 tetrahedra, edges with seven FLa4S3 tetrahedra, a faceface with one FLa4S4 tetrahedra, and faces with two equivalent OLa4S4 tetrahedra. In the eighth F1- site, F1- is bonded to four La3+ and three S2- atoms to form distorted FLa4S3 tetrahedra that share corners with two equivalent OLa4S4 tetrahedra, corners with three FLa4S4 tetrahedra, an edgeedge with one OLa4S4 tetrahedra, edges with six FLa4S3 tetrahedra, a faceface with one FLa4S4 tetrahedra, and faces with two equivalent OLa4S4 tetrahedra. In the ninth F1- site, F1- is bonded to four La3+ and three S2- atoms to form FLa4S3 tetrahedra that share a cornercorner with one FLa4S4 tetrahedra, corners with four OLa4S4 tetrahedra, edges with seven FLa4S3 tetrahedra, and faces with three OLa4S4 tetrahedra. In the tenth F1- site, F1- is bonded to four La3+ and three S2- atoms to form FLa4S3 tetrahedra that share corners with two equivalent FLa4S4 tetrahedra, corners with three OLa4S4 tetrahedra, an edgeedge with one OLa4S4 tetrahedra, edges with six FLa4S3 tetrahedra, a faceface with one OLa4S4 tetrahedra, and faces with two equivalent FLa4S4 tetrahedra. In the eleventh F1- site, F1- is bonded to four La3+ and three S2- atoms to form distorted FLa4S3 tetrahedra that share corners with two equivalent FLa4S4 tetrahedra, corners with three OLa4S4 tetrahedra, an edgeedge with one OLa4S4 tetrahedra, edges with six FLa4S3 tetrahedra, and faces with three OLa4S4 tetrahedra. In the twelfth F1- site, F1- is bonded to four La3+ and three S2- atoms to form distorted FLa4S3 tetrahedra that share corners with five OLa4S4 tetrahedra, an edgeedge with one OLa4S4 tetrahedra, edges with six FLa4S3 tetrahedra, a faceface with one OLa4S4 tetrahedra, and faces with two equivalent FLa4S4 tetrahedra. In the thirteenth F1- site, F1- is bonded in a trigonal planar geometry to three La3+ and six S2- atoms. In the fourteenth F1- site, F1- is bonded in a distorted trigonal planar geometry to three La3+ and six S2- atoms. In the fifteenth F1- site, F1- is bonded to four La3+ and four S2- atoms to form FLa4S4 tetrahedra that share corners with five OLa4S4 tetrahedra, corners with six FLa4S4 tetrahedra, edges with three FLa4S4 tetrahedra, faces with two equivalent OLa4S4 tetrahedra, and faces with three FLa4S3 tetrahedra. In the sixteenth F1- site, F1- is bonded to four La3+ and four S2- atoms to form FLa4S4 tetrahedra that share corners with five OLa4S4 tetrahedra, corners with six FLa4S3 tetrahedra, edges with three FLa4S4 tetrahedra, faces with two equivalent OLa4S4 tetrahedra, and faces with three FLa4S3 tetrahedra.