DOE OSTI2020
Li2NH crystallizes in the orthorhombic Ima2 space group. The structure is three-dimensional. there are six inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to two equivalent Li1+ and four N3- atoms to form distorted corner-sharing LiLi2N4 tetrahedra. There are one shorter (2.21 Å) and one longer (2.39 Å) Li–Li bond lengths. There are a spread of Li–N bond distances ranging from 1.95–2.07 Å. In the second Li1+ site, Li1+ is bonded in a 2-coordinate geometry to four N3- and two equivalent H1+ atoms. There are a spread of Li–N bond distances ranging from 2.15–2.32 Å. Both Li–H bond lengths are 2.19 Å. In the third Li1+ site, Li1+ is bonded in a 8-coordinate geometry to two equivalent Li1+, four N3-, and two H1+ atoms. There are one shorter (2.20 Å) and one longer (2.25 Å) Li–Li bond lengths. There are a spread of Li–N bond distances ranging from 2.12–2.17 Å. There is one shorter (1.93 Å) and one longer (2.00 Å) Li–H bond length. In the fourth Li1+ site, Li1+ is bonded in a 2-coordinate geometry to one Li1+, three N3-, and two H1+ atoms. The Li–Li bond length is 2.34 Å. There are two shorter (2.12 Å) and one longer (2.14 Å) Li–N bond lengths. There are one shorter (2.07 Å) and one longer (2.11 Å) Li–H bond lengths. In the fifth Li1+ site, Li1+ is bonded in a 2-coordinate geometry to one Li1+, three N3-, and two H1+ atoms. The Li–Li bond length is 2.26 Å. There are a spread of Li–N bond distances ranging from 2.10–2.14 Å. There are one shorter (2.04 Å) and one longer (2.18 Å) Li–H bond lengths. In the sixth Li1+ site, Li1+ is bonded in a 5-coordinate geometry to eight Li1+ and six N3- atoms. There are a spread of Li–N bond distances ranging from 2.28–2.56 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted single-bond geometry to eight Li1+ and one H1+ atom. The N–H bond length is 1.04 Å. In the second N3- site, N3- is bonded in a distorted single-bond geometry to eight Li1+ and one H1+ atom. The N–H bond length is 1.04 Å. In the third N3- site, N3- is bonded in a distorted single-bond geometry to seven Li1+ and one H1+ atom. The N–H bond length is 1.03 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to three Li1+ and one N3- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to three Li1+ and one N3- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to three Li1+ and one N3- atom.