DOE OSTI2019
Li44Sr19 is Bergman Structure: Mg32(Al,Zn)49 Bergman-derived structured and crystallizes in the tetragonal I-42d space group. The structure is three-dimensional. there are twelve inequivalent Li sites. In the first Li site, Li is bonded in a 9-coordinate geometry to six Li and five Sr atoms. There are a spread of Li–Li bond distances ranging from 3.02–3.36 Å. There are a spread of Li–Sr bond distances ranging from 3.65–3.95 Å. In the second Li site, Li is bonded in a 12-coordinate geometry to seven Li and five Sr atoms. There are a spread of Li–Li bond distances ranging from 2.94–3.26 Å. There are a spread of Li–Sr bond distances ranging from 3.63–3.96 Å. In the third Li site, Li is bonded in a 11-coordinate geometry to six Li and five Sr atoms. There are a spread of Li–Li bond distances ranging from 2.91–3.25 Å. There are a spread of Li–Sr bond distances ranging from 3.60–3.92 Å. In the fourth Li site, Li is bonded to twelve Li atoms to form face-sharing LiLi12 cuboctahedra. There are a spread of Li–Li bond distances ranging from 2.76–3.11 Å. In the fifth Li site, Li is bonded in a 2-coordinate geometry to three Li and five Sr atoms. There are one shorter (3.16 Å) and one longer (3.27 Å) Li–Li bond lengths. There are a spread of Li–Sr bond distances ranging from 3.84–3.98 Å. In the sixth Li site, Li is bonded to eight Li and four Sr atoms to form distorted LiSr4Li8 cuboctahedra that share corners with two equivalent LiSr5Li7 cuboctahedra, edges with two LiSr4Li8 cuboctahedra, and faces with four LiLi12 cuboctahedra. There are a spread of Li–Li bond distances ranging from 3.00–3.18 Å. There are a spread of Li–Sr bond distances ranging from 3.74–3.86 Å. In the seventh Li site, Li is bonded to seven Li and five Sr atoms to form distorted LiSr5Li7 cuboctahedra that share corners with four LiSr4Li8 cuboctahedra, an edgeedge with one LiSr4Li8 cuboctahedra, and faces with three LiLi12 cuboctahedra. There are one shorter (3.02 Å) and one longer (3.23 Å) Li–Li bond lengths. There are a spread of Li–Sr bond distances ranging from 3.67–3.86 Å. In the eighth Li site, Li is bonded in a 2-coordinate geometry to seven Li and five Sr atoms. The Li–Li bond length is 3.31 Å. There are a spread of Li–Sr bond distances ranging from 3.66–3.86 Å. In the ninth Li site, Li is bonded in a 12-coordinate geometry to eight Li and three Sr atoms. The Li–Li bond length is 3.05 Å. There are a spread of Li–Sr bond distances ranging from 3.65–3.91 Å. In the tenth Li site, Li is bonded in a 12-coordinate geometry to seven Li and five Sr atoms. There are one shorter (3.01 Å) and one longer (3.03 Å) Li–Li bond lengths. There are a spread of Li–Sr bond distances ranging from 3.68–3.91 Å. In the eleventh Li site, Li is bonded in a 12-coordinate geometry to eight Li and four Sr atoms. There are two shorter (3.63 Å) and two longer (3.90 Å) Li–Sr bond lengths. In the twelfth Li site, Li is bonded in a 8-coordinate geometry to six Li and two equivalent Sr atoms. Both Li–Sr bond lengths are 3.80 Å. There are six inequivalent Sr sites. In the first Sr site, Sr is bonded in a 12-coordinate geometry to twelve Li and four equivalent Sr atoms. All Sr–Sr bond lengths are 4.06 Å. In the second Sr site, Sr is bonded in a 4-coordinate geometry to six Li and six Sr atoms. There are a spread of Sr–Sr bond distances ranging from 4.11–4.26 Å. In the third Sr site, Sr is bonded in a 2-coordinate geometry to eleven Li and six Sr atoms. There are a spread of Sr–Sr bond distances ranging from 4.06–4.50 Å. In the fourth Sr site, Sr is bonded in a 12-coordinate geometry to eight Li and five Sr atoms. Both Sr–Sr bond lengths are 4.04 Å. In the fifth Sr site, Sr is bonded in a 5-coordinate geometry to nine Li and six Sr atoms. Both Sr–Sr bond lengths are 4.19 Å. In the sixth Sr site, Sr is bonded in a 4-coordinate geometry to eleven Li and five Sr atoms. The Sr–Sr bond length is 4.38 Å.