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YB2 is hexagonal omega structure structured and crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Y is bonded to twelve equivalent B atoms to form a mixture of edge and face-sharing YB12 cuboctahedra. All Y–B bond lengths are 2.71 Å. B is bonded in a 9-coordinate geometry to six equivalent Y and three equivalent B atoms. All B–B bond lengths are 1.91 Å.
YB6 is Calcium hexaboride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Y is bonded in a 1-coordinate geometry to twenty-four equivalent B atoms. All Y–B bond lengths are 3.01 Å. B is bonded in a 1-coordinate geometry to four equivalent Y and five equivalent B atoms. There is one shorter (1.63 Å) and four longer (1.75 Å) B–B bond length.
YB4 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Y is bonded in a 4-coordinate geometry to eighteen B atoms. There are a spread of Y–B bond distances ranging from 2.73–3.07 Å. There are three inequivalent B sites. In the first B site, B is bonded in a 1-coordinate geometry to four equivalent Y and five B atoms. There is one shorter (1.64 Å) and four longer (1.75 Å) B–B bond length. In the second B site, B is bonded in a 9-coordinate geometry to four equivalent Y and five B atoms. There is one shorter (1.72 Å) and two longer (1.81 Å) B–B bond length. In the third B site, B is bonded in a distorted trigonal planar geometry to six equivalent Y and three B atoms. The B–B bond length is 1.75 Å.
YB12 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Y is bonded in a 1-coordinate geometry to twenty-four equivalent B atoms. All Y–B bond lengths are 2.79 Å. B is bonded in a 7-coordinate geometry to two equivalent Y and five equivalent B atoms. There is one shorter (1.72 Å) and four longer (1.79 Å) B–B bond length.