YAl2BN4 is beta beryllia-derived structured and crystallizes in the monoclinic Pm space group. Y(1) is bonded to one N(2), one N(4), and two equivalent N(1) atoms to form YN4 tetrahedra that share corners with two equivalent Y(1)N4 tetrahedra, corners with two equivalent Al(1)N4 tetrahedra, corners with four equivalent Al(2)N4 tetrahedra, and corners with four equivalent B(1)N4 tetrahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one N(2), one N(4), and two equivalent N(3) atoms to form AlN4 tetrahedra that share corners with two equivalent Y(1)N4 tetrahedra, corners with two equivalent Al(1)N4 tetrahedra, corners with four equivalent Al(2)N4 tetrahedra, and corners with four equivalent B(1)N4 tetrahedra. In the second Al site, Al(2) is bonded to one N(1), one N(3), and two equivalent N(4) atoms to form AlN4 tetrahedra that share corners with two equivalent Al(2)N4 tetrahedra, corners with two equivalent B(1)N4 tetrahedra, corners with four equivalent Y(1)N4 tetrahedra, and corners with four equivalent Al(1)N4 tetrahedra. B(1) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form BN4 tetrahedra that share corners with two equivalent Al(2)N4 tetrahedra, corners with two equivalent B(1)N4 tetrahedra, corners with four equivalent Y(1)N4 tetrahedra, and corners with four equivalent Al(1)N4 tetrahedra. There are four inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Y(1), one Al(2), and one B(1) atom to form distorted NY2AlB trigonal pyramids that share corners with two equivalent N(3)Al3B tetrahedra, corners with four equivalent N(4)YAl3 tetrahedra, corners with four equivalent N(2)YAlB2 tetrahedra, and corners with two equivalent N(1)Y2AlB trigonal pyramids. In the second N site, N(2) is bonded to one Y(1), one Al(1), and two equivalent B(1) atoms to form distorted NYAlB2 tetrahedra that share corners with two equivalent N(4)YAl3 tetrahedra, corners with two equivalent N(2)YAlB2 tetrahedra, corners with four equivalent N(3)Al3B tetrahedra, and corners with four equivalent N(1)Y2AlB trigonal pyramids. In the third N site, N(3) is bonded to one Al(2), two equivalent Al(1), and one B(1) atom to form NAl3B tetrahedra that share corners with two equivalent N(3)Al3B tetrahedra, corners with four equivalent N(4)YAl3 tetrahedra, corners with four equivalent N(2)YAlB2 tetrahedra, and corners with two equivalent N(1)Y2AlB trigonal pyramids. In the fourth N site, N(4) is bonded to one Y(1), one Al(1), and two equivalent Al(2) atoms to form NYAl3 tetrahedra that share corners with two equivalent N(4)YAl3 tetrahedra, corners with two equivalent N(2)YAlB2 tetrahedra, corners with four equivalent N(3)Al3B tetrahedra, and corners with four equivalent N(1)Y2AlB trigonal pyramids.
YAl2BN4 is beta beryllia-derived structured and crystallizes in the monoclinic Pm space group. Y(1) is bonded to one N(2), one N(4), and two equivalent N(1) atoms to form YN4 tetrahedra that share corners with two equivalent Y(1)N4 tetrahedra, corners with two equivalent Al(1)N4 tetrahedra, corners with four equivalent Al(2)N4 tetrahedra, and corners with four equivalent B(1)N4 tetrahedra. The Y(1)-N(2) bond length is 2.20 Å. The Y(1)-N(4) bond length is 2.20 Å. Both Y(1)-N(1) bond lengths are 2.22 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one N(2), one N(4), and two equivalent N(3) atoms to form AlN4 tetrahedra that share corners with two equivalent Y(1)N4 tetrahedra, corners with two equivalent Al(1)N4 tetrahedra, corners with four equivalent Al(2)N4 tetrahedra, and corners with four equivalent B(1)N4 tetrahedra. The Al(1)-N(2) bond length is 1.87 Å. The Al(1)-N(4) bond length is 1.85 Å. Both Al(1)-N(3) bond lengths are 1.93 Å. In the second Al site, Al(2) is bonded to one N(1), one N(3), and two equivalent N(4) atoms to form AlN4 tetrahedra that share corners with two equivalent Al(2)N4 tetrahedra, corners with two equivalent B(1)N4 tetrahedra, corners with four equivalent Y(1)N4 tetrahedra, and corners with four equivalent Al(1)N4 tetrahedra. The Al(2)-N(1) bond length is 2.01 Å. The Al(2)-N(3) bond length is 2.04 Å. Both Al(2)-N(4) bond lengths are 1.88 Å. B(1) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form BN4 tetrahedra that share corners with two equivalent Al(2)N4 tetrahedra, corners with two equivalent B(1)N4 tetrahedra, corners with four equivalent Y(1)N4 tetrahedra, and corners with four equivalent Al(1)N4 tetrahedra. The B(1)-N(1) bond length is 1.65 Å. The B(1)-N(3) bond length is 1.66 Å. Both B(1)-N(2) bond lengths are 1.78 Å. There are four inequivalent N sites. In the first N site, N(1) is bonded to two equivalent Y(1), one Al(2), and one B(1) atom to form distorted NY2AlB trigonal pyramids that share corners with two equivalent N(3)Al3B tetrahedra, corners with four equivalent N(4)YAl3 tetrahedra, corners with four equivalent N(2)YAlB2 tetrahedra, and corners with two equivalent N(1)Y2AlB trigonal pyramids. In the second N site, N(2) is bonded to one Y(1), one Al(1), and two equivalent B(1) atoms to form distorted NYAlB2 tetrahedra that share corners with two equivalent N(4)YAl3 tetrahedra, corners with two equivalent N(2)YAlB2 tetrahedra, corners with four equivalent N(3)Al3B tetrahedra, and corners with four equivalent N(1)Y2AlB trigonal pyramids. In the third N site, N(3) is bonded to one Al(2), two equivalent Al(1), and one B(1) atom to form NAl3B tetrahedra that share corners with two equivalent N(3)Al3B tetrahedra, corners with four equivalent N(4)YAl3 tetrahedra, corners with four equivalent N(2)YAlB2 tetrahedra, and corners with two equivalent N(1)Y2AlB trigonal pyramids. In the fourth N site, N(4) is bonded to one Y(1), one Al(1), and two equivalent Al(2) atoms to form NYAl3 tetrahedra that share corners with two equivalent N(4)YAl3 tetrahedra, corners with two equivalent N(2)YAlB2 tetrahedra, corners with four equivalent N(3)Al3B tetrahedra, and corners with four equivalent N(1)Y2AlB trigonal pyramids.