BeAlSiN3 is Stannite-like structured and crystallizes in the monoclinic Cc space group. Be(1) is bonded to one N(2), one N(3), and two equivalent N(1) atoms to form BeN4 tetrahedra that share corners with two equivalent Be(1)N4 tetrahedra, corners with five equivalent Al(1)N4 tetrahedra, and corners with five equivalent Si(1)N4 tetrahedra. Al(1) is bonded to one N(1), one N(2), and two equivalent N(3) atoms to form AlN4 tetrahedra that share corners with two equivalent Al(1)N4 tetrahedra, corners with five equivalent Be(1)N4 tetrahedra, and corners with five equivalent Si(1)N4 tetrahedra. Si(1) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form SiN4 tetrahedra that share corners with two equivalent Si(1)N4 tetrahedra, corners with five equivalent Be(1)N4 tetrahedra, and corners with five equivalent Al(1)N4 tetrahedra. There are three inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Be(1), one Al(1), and one Si(1) atom to form NBe2AlSi tetrahedra that share corners with two equivalent N(1)Be2AlSi tetrahedra, corners with five equivalent N(3)BeAl2Si tetrahedra, and corners with five equivalent N(2)BeAlSi2 tetrahedra. In the second N site, N(2) is bonded to one Be(1), one Al(1), and two equivalent Si(1) atoms to form NBeAlSi2 tetrahedra that share corners with two equivalent N(2)BeAlSi2 tetrahedra, corners with five equivalent N(1)Be2AlSi tetrahedra, and corners with five equivalent N(3)BeAl2Si tetrahedra. In the third N site, N(3) is bonded to one Be(1), two equivalent Al(1), and one Si(1) atom to form NBeAl2Si tetrahedra that share corners with two equivalent N(3)BeAl2Si tetrahedra, corners with five equivalent N(1)Be2AlSi tetrahedra, and corners with five equivalent N(2)BeAlSi2 tetrahedra.
BeAlSiN3 is Stannite-like structured and crystallizes in the monoclinic Cc space group. Be(1) is bonded to one N(2), one N(3), and two equivalent N(1) atoms to form BeN4 tetrahedra that share corners with two equivalent Be(1)N4 tetrahedra, corners with five equivalent Al(1)N4 tetrahedra, and corners with five equivalent Si(1)N4 tetrahedra. The Be(1)-N(2) bond length is 1.83 Å. The Be(1)-N(3) bond length is 1.77 Å. There is one shorter (1.77 Å) and one longer (1.82 Å) Be(1)-N(1) bond length. Al(1) is bonded to one N(1), one N(2), and two equivalent N(3) atoms to form AlN4 tetrahedra that share corners with two equivalent Al(1)N4 tetrahedra, corners with five equivalent Be(1)N4 tetrahedra, and corners with five equivalent Si(1)N4 tetrahedra. The Al(1)-N(1) bond length is 1.87 Å. The Al(1)-N(2) bond length is 1.90 Å. Both Al(1)-N(3) bond lengths are 1.88 Å. Si(1) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form SiN4 tetrahedra that share corners with two equivalent Si(1)N4 tetrahedra, corners with five equivalent Be(1)N4 tetrahedra, and corners with five equivalent Al(1)N4 tetrahedra. The Si(1)-N(1) bond length is 1.74 Å. The Si(1)-N(3) bond length is 1.74 Å. There is one shorter (1.78 Å) and one longer (1.80 Å) Si(1)-N(2) bond length. There are three inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Be(1), one Al(1), and one Si(1) atom to form NBe2AlSi tetrahedra that share corners with two equivalent N(1)Be2AlSi tetrahedra, corners with five equivalent N(3)BeAl2Si tetrahedra, and corners with five equivalent N(2)BeAlSi2 tetrahedra. In the second N site, N(2) is bonded to one Be(1), one Al(1), and two equivalent Si(1) atoms to form NBeAlSi2 tetrahedra that share corners with two equivalent N(2)BeAlSi2 tetrahedra, corners with five equivalent N(1)Be2AlSi tetrahedra, and corners with five equivalent N(3)BeAl2Si tetrahedra. In the third N site, N(3) is bonded to one Be(1), two equivalent Al(1), and one Si(1) atom to form NBeAl2Si tetrahedra that share corners with two equivalent N(3)BeAl2Si tetrahedra, corners with five equivalent N(1)Be2AlSi tetrahedra, and corners with five equivalent N(2)BeAlSi2 tetrahedra.