DOE OSTI2020
Li2Sr4B12O23 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Li1+ is bonded in a 4-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 1.95–2.48 Å. There are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.60–3.01 Å. In the second Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.55–2.90 Å. There are six inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.36–1.41 Å. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.36–1.40 Å. In the third B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There is three shorter (1.47 Å) and one longer (1.56 Å) B–O bond length. In the fourth B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.45–1.51 Å. In the fifth B3+ site, B3+ is bonded to four O2- atoms to form corner-sharing BO4 tetrahedra. There are a spread of B–O bond distances ranging from 1.45–1.58 Å. In the sixth B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of B–O bond distances ranging from 1.36–1.44 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sr2+, and two B3+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three Sr2+ and one B3+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sr2+, and two B3+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Li1+ and two B3+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Sr2+ and two B3+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+, two equivalent Sr2+, and one B3+ atom. In the seventh O2- site, O2- is bonded in a trigonal planar geometry to one Li1+ and two B3+ atoms. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Sr2+ and two B3+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Sr2+ and two B3+ atoms. In the tenth O2- site, O2- is bonded in a linear geometry to two equivalent Sr2+ and two equivalent B3+ atoms. In the eleventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Sr2+ and two B3+ atoms. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Sr2+ and two B3+ atoms.