LiCa3Si2N5 crystallizes in the monoclinic C2/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted bent 150 degrees geometry to two equivalent N(2) and two equivalent N(5) atoms. In the second Li site, Li(2) is bonded in a distorted bent 120 degrees geometry to two equivalent N(2), two equivalent N(3), and two equivalent N(5) atoms. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one N(4), two equivalent N(5), and three equivalent N(1) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one N(1), one N(2), one N(3), and three equivalent N(4) atoms. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to one N(2), one N(4), and four equivalent N(3) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one N(2), one N(3), one N(4), and one N(5) atom to form corner-sharing SiN4 tetrahedra. In the second Si site, Si(2) is bonded to one N(2), one N(5), and two equivalent N(1) atoms to form a mixture of corner and edge-sharing SiN4 tetrahedra. There are five inequivalent N sites. In the first N site, N(5) is bonded in a 6-coordinate geometry to one Li(1), one Li(2), two equivalent Ca(1), one Si(1), and one Si(2) atom. In the second N site, N(1) is bonded in a 6-coordinate geometry to one Ca(2), three equivalent Ca(1), and two equivalent Si(2) atoms. In the third N site, N(2) is bonded in a 6-coordinate geometry to one Li(1), one Li(2), one Ca(2), one Ca(3), one Si(1), and one Si(2) atom. In the fourth N site, N(3) is bonded in a 7-coordinate geometry to one Li(2), one Ca(2), four equivalent Ca(3), and one Si(1) atom. In the fifth N site, N(4) is bonded to one Ca(1), one Ca(3), three equivalent Ca(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing NCa5Si octahedra. The corner-sharing octahedral tilt angles are 10°.
LiCa3Si2N5 crystallizes in the monoclinic C2/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted bent 150 degrees geometry to two equivalent N(2) and two equivalent N(5) atoms. Both Li(1)-N(2) bond lengths are 2.01 Å. Both Li(1)-N(5) bond lengths are 2.58 Å. In the second Li site, Li(2) is bonded in a distorted bent 120 degrees geometry to two equivalent N(2), two equivalent N(3), and two equivalent N(5) atoms. Both Li(2)-N(2) bond lengths are 2.62 Å. Both Li(2)-N(3) bond lengths are 2.66 Å. Both Li(2)-N(5) bond lengths are 2.08 Å. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one N(4), two equivalent N(5), and three equivalent N(1) atoms. The Ca(1)-N(4) bond length is 2.41 Å. There is one shorter (2.39 Å) and one longer (2.65 Å) Ca(1)-N(5) bond length. There are a spread of Ca(1)-N(1) bond distances ranging from 2.49-2.71 Å. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one N(1), one N(2), one N(3), and three equivalent N(4) atoms. The Ca(2)-N(1) bond length is 2.82 Å. The Ca(2)-N(2) bond length is 2.54 Å. The Ca(2)-N(3) bond length is 2.53 Å. There are a spread of Ca(2)-N(4) bond distances ranging from 2.35-2.66 Å. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to one N(2), one N(4), and four equivalent N(3) atoms. The Ca(3)-N(2) bond length is 2.39 Å. The Ca(3)-N(4) bond length is 2.40 Å. There are a spread of Ca(3)-N(3) bond distances ranging from 2.53-2.87 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one N(2), one N(3), one N(4), and one N(5) atom to form corner-sharing SiN4 tetrahedra. The Si(1)-N(2) bond length is 1.81 Å. The Si(1)-N(3) bond length is 1.75 Å. The Si(1)-N(4) bond length is 1.76 Å. The Si(1)-N(5) bond length is 1.79 Å. In the second Si site, Si(2) is bonded to one N(2), one N(5), and two equivalent N(1) atoms to form a mixture of corner and edge-sharing SiN4 tetrahedra. The Si(2)-N(2) bond length is 1.73 Å. The Si(2)-N(5) bond length is 1.75 Å. There is one shorter (1.80 Å) and one longer (1.82 Å) Si(2)-N(1) bond length. There are five inequivalent N sites. In the first N site, N(5) is bonded in a 6-coordinate geometry to one Li(1), one Li(2), two equivalent Ca(1), one Si(1), and one Si(2) atom. In the second N site, N(1) is bonded in a 6-coordinate geometry to one Ca(2), three equivalent Ca(1), and two equivalent Si(2) atoms. In the third N site, N(2) is bonded in a 6-coordinate geometry to one Li(1), one Li(2), one Ca(2), one Ca(3), one Si(1), and one Si(2) atom. In the fourth N site, N(3) is bonded in a 7-coordinate geometry to one Li(2), one Ca(2), four equivalent Ca(3), and one Si(1) atom. In the fifth N site, N(4) is bonded to one Ca(1), one Ca(3), three equivalent Ca(2), and one Si(1) atom to form a mixture of distorted corner and edge-sharing NCa5Si octahedra. The corner-sharing octahedral tilt angles are 10°.