DOI: 10.17188/1653022
title: Materials Data on Sc2Al4(CO)3 by Materials Project

description: Sc2Al4(CO)3 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are two inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded to six C4- atoms to form distorted ScC6 octahedra that share corners with three equivalent AlC4 tetrahedra, corners with three equivalent AlC3O trigonal pyramids, edges with six equivalent ScC6 octahedra, edges with three equivalent AlC4 tetrahedra, and edges with three equivalent AlC3O trigonal pyramids. There are three shorter (2.26 Å) and three longer (2.66 Å) Sc–C bond lengths. In the second Sc3+ site, Sc3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.06 Å) and three longer (2.31 Å) Sc–O bond lengths. There are four inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to three equivalent C4- and one O2- atom to form AlC3O trigonal pyramids that share corners with three equivalent AlC4 tetrahedra and corners with six equivalent AlC3O trigonal pyramids. All Al–C bond lengths are 1.97 Å. The Al–O bond length is 1.91 Å. In the second Al3+ site, Al3+ is bonded in a 4-coordinate geometry to one C4- and four O2- atoms. The Al–C bond length is 2.48 Å. There is one shorter (1.75 Å) and three longer (1.96 Å) Al–O bond length. In the third Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent ScC6 octahedra, corners with six equivalent AlC4 tetrahedra, corners with three equivalent AlC3O trigonal pyramids, and edges with three equivalent ScC6 octahedra. The corner-sharing octahedral tilt angles are 4°. There are one shorter (1.92 Å) and three longer (2.18 Å) Al–C bond lengths. In the fourth Al3+ site, Al3+ is bonded to three equivalent C4- and one O2- atom to form AlC3O trigonal pyramids that share corners with three equivalent ScC6 octahedra, corners with six equivalent AlC3O trigonal pyramids, and edges with three equivalent ScC6 octahedra. The corner-sharing octahedral tilt angles are 34°. All Al–C bond lengths are 1.97 Å. The Al–O bond length is 1.91 Å. There are three inequivalent C4- sites. In the first C4- site, C4- is bonded to three equivalent Sc3+ and three equivalent Al3+ atoms to form CSc3Al3 octahedra that share corners with three equivalent CAl4 trigonal pyramids and edges with six equivalent CSc3Al3 octahedra. In the second C4- site, C4- is bonded in a 3-coordinate geometry to three equivalent Sc3+ and four Al3+ atoms. In the third C4- site, C4- is bonded to four Al3+ atoms to form distorted CAl4 trigonal pyramids that share corners with three equivalent CSc3Al3 octahedra, corners with three equivalent OSc3Al tetrahedra, and corners with six equivalent CAl4 trigonal pyramids. The corner-sharing octahedral tilt angles are 63°. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Sc3+ and one Al3+ atom. In the second O2- site, O2- is bonded to three equivalent Sc3+ and one Al3+ atom to form OSc3Al tetrahedra that share corners with six equivalent OSc3Al tetrahedra and corners with three equivalent CAl4 trigonal pyramids. In the third O2- site, O2- is bonded to four Al3+ atoms to form corner-sharing OAl4 trigonal pyramids.