SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Zr2AlC is H-Phase structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Zr is bonded in a 3-coordinate geometry to three equivalent Al and three equivalent C atoms. All Zr–Al bond lengths are 3.06 Å. All Zr–C bond lengths are 2.30 Å. Al is bonded in a 6-coordinate geometry to six equivalent Zr atoms. C is bonded to six equivalent Zr atoms to form edge-sharing CZr6 octahedra.
Zr2Al3C4 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Zr+3.50+ is bonded to six C4- atoms to form ZrC6 octahedra that share corners with three equivalent ZrC6 octahedra, corners with three equivalent AlC4 tetrahedra, edges with nine equivalent ZrC6 octahedra, and edges with three equivalent AlC4 tetrahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.34 Å) and three longer (2.50 Å) Zr–C bond lengths. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent ZrC6 octahedra, corners with seven equivalent AlC4 tetrahedra, and edges with three equivalent ZrC6 octahedra. The corner-sharing octahedral tilt angles are 20°. There are one shorter (2.02 Å) and three longer (2.06 Å) Al–C bond lengths. In the second Al3+ site, Al3+ is bonded in a trigonal planar geometry to three equivalent C4- atoms. All Al–C bond lengths are 1.94 Å. There are three inequivalent C4- sites. In the first C4- site, C4- is bonded in a 6-coordinate geometry to three equivalent Zr+3.50+ and three equivalent Al3+ atoms. In the second C4- site, C4- is bonded to six equivalent Zr+3.50+ atoms to form edge-sharing CZr6 octahedra. In the third C4- site, C4- is bonded to five Al3+ atoms to form corner-sharing CAl5 trigonal bipyramids.
Zr2Al3C4 crystallizes in the hexagonal P6_3mc space group. The structure is two-dimensional and consists of two aluminum molecules and two AlZrC2 sheets oriented in the (0, 0, 1) direction. In each AlZrC2 sheet, there are two inequivalent Zr+3.50+ sites. In the first Zr+3.50+ site, Zr+3.50+ is bonded to six C4- atoms to form ZrC6 octahedra that share corners with three equivalent AlC6 octahedra, edges with three equivalent AlC6 octahedra, and edges with six equivalent ZrC6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are three shorter (2.33 Å) and three longer (2.37 Å) Zr–C bond lengths. In the second Zr+3.50+ site, Zr+3.50+ is bonded in a distorted T-shaped geometry to three equivalent C4- atoms. All Zr–C bond lengths are 2.25 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six C4- atoms to form AlC6 octahedra that share corners with three equivalent ZrC6 octahedra, corners with three equivalent CAl3C tetrahedra, edges with three equivalent ZrC6 octahedra, and edges with six equivalent AlC6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are three shorter (2.13 Å) and three longer (2.34 Å) Al–C bond lengths. In the second Al3+ site, Al3+ is bonded in a trigonal non-coplanar geometry to three equivalent C4- atoms. All Al–C bond lengths are 2.09 Å. There are four inequivalent C4- sites. In the first C4- site, C4- is bonded to three equivalent Al3+ and one C4- atom to form CAl3C tetrahedra that share corners with three equivalent AlC6 octahedra and corners with six equivalent CAl3C tetrahedra. The corner-sharing octahedral tilt angles are 53°. The C–C bond length is 1.31 Å. In the second C4- site, C4- is bonded to three equivalent Zr+3.50+ and three equivalent Al3+ atoms to form CZr3Al3 octahedra that share corners with three equivalent CZr6 octahedra and edges with nine CZr3Al3 octahedra. The corner-sharing octahedral tilt angles are 1°. In the third C4- site, C4- is bonded to six Zr+3.50+ atoms to form a mixture of edge and corner-sharing CZr6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the fourth C4- site, C4- is bonded in a rectangular see-saw-like geometry to three equivalent Al3+ and one C4- atom.
Zr4(AlC2)3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Zr+3.75+ sites. In the first Zr+3.75+ site, Zr+3.75+ is bonded to six C4- atoms to form a mixture of edge and corner-sharing ZrC6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are three shorter (2.36 Å) and three longer (2.41 Å) Zr–C bond lengths. In the second Zr+3.75+ site, Zr+3.75+ is bonded to six C4- atoms to form ZrC6 octahedra that share corners with three equivalent ZrC6 octahedra, corners with three equivalent AlC4 tetrahedra, edges with nine ZrC6 octahedra, and edges with three equivalent AlC4 tetrahedra. The corner-sharing octahedral tilt angles are 3°. There are three shorter (2.31 Å) and three longer (2.51 Å) Zr–C bond lengths. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent ZrC6 octahedra, corners with seven equivalent AlC4 tetrahedra, and edges with three equivalent ZrC6 octahedra. The corner-sharing octahedral tilt angles are 20°. There are one shorter (2.02 Å) and three longer (2.06 Å) Al–C bond lengths. In the second Al3+ site, Al3+ is bonded in a trigonal planar geometry to three equivalent C4- atoms. All Al–C bond lengths are 1.94 Å. There are four inequivalent C4- sites. In the first C4- site, C4- is bonded to six Zr+3.75+ atoms to form a mixture of edge and corner-sharing CZr6 octahedra. The corner-sharing octahedral tilt angles are 2°. In the second C4- site, C4- is bonded in a 6-coordinate geometry to three equivalent Zr+3.75+ and three equivalent Al3+ atoms. In the third C4- site, C4- is bonded to five Al3+ atoms to form corner-sharing CAl5 trigonal bipyramids. In the fourth C4- site, C4- is bonded to six equivalent Zr+3.75+ atoms to form a mixture of edge and corner-sharing CZr6 octahedra. The corner-sharing octahedral tilt angles are 2°.
Zr3Al4C6 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are three inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing ZrC6 octahedra. The corner-sharing octahedral tilt angles are 1°. All Zr–C bond lengths are 2.38 Å. In the second Zr4+ site, Zr4+ is bonded to six C4- atoms to form ZrC6 octahedra that share corners with three equivalent ZrC6 octahedra, corners with three equivalent AlC4 tetrahedra, edges with nine ZrC6 octahedra, and edges with three equivalent AlC4 tetrahedra. The corner-sharing octahedral tilt angles are 1°. There are three shorter (2.35 Å) and three longer (2.40 Å) Zr–C bond lengths. In the third Zr4+ site, Zr4+ is bonded to six C4- atoms to form ZrC6 octahedra that share corners with three equivalent ZrC6 octahedra, corners with three equivalent AlC4 tetrahedra, edges with nine ZrC6 octahedra, and edges with three equivalent AlC4 tetrahedra. The corner-sharing octahedral tilt angles are 1°. There are three shorter (2.35 Å) and three longer (2.40 Å) Zr–C bond lengths. There are four inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four C4- atoms to form a mixture of corner and edge-sharing AlC4 trigonal pyramids. There are three shorter (1.96 Å) and one longer (2.18 Å) Al–C bond lengths. In the second Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent ZrC6 octahedra, corners with six equivalent AlC4 tetrahedra, corners with four AlC4 trigonal pyramids, and edges with three equivalent ZrC6 octahedra. The corner-sharing octahedral tilt angles are 12°. There are one shorter (1.95 Å) and three longer (2.13 Å) Al–C bond lengths. In the third Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent ZrC6 octahedra, corners with six equivalent AlC4 tetrahedra, corners with four AlC4 trigonal pyramids, and edges with three equivalent ZrC6 octahedra. The corner-sharing octahedral tilt angles are 12°. There are one shorter (1.95 Å) and three longer (2.13 Å) Al–C bond lengths. In the fourth Al3+ site, Al3+ is bonded to four C4- atoms to form a mixture of corner and edge-sharing AlC4 trigonal pyramids. There are three shorter (1.96 Å) and one longer (2.18 Å) Al–C bond lengths. There are six inequivalent C4- sites. In the first C4- site, C4- is bonded to five Al3+ atoms to form CAl5 trigonal bipyramids that share corners with three equivalent CZr3Al3 octahedra, corners with six equivalent CAl5 trigonal bipyramids, and edges with three equivalent CAl5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 65°. In the second C4- site, C4- is bonded to three equivalent Zr4+ and three equivalent Al3+ atoms to form CZr3Al3 octahedra that share corners with three equivalent CZr6 octahedra, corners with three equivalent CAl5 trigonal bipyramids, and edges with nine CZr6 octahedra. The corner-sharing octahedral tilt angles are 2°. In the third C4- site, C4- is bonded to five Al3+ atoms to form CAl5 trigonal bipyramids that share corners with three equivalent CZr3Al3 octahedra, corners with six equivalent CAl5 trigonal bipyramids, and edges with three equivalent CAl5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 66°. In the fourth C4- site, C4- is bonded to six Zr4+ atoms to form a mixture of corner and edge-sharing CZr6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the fifth C4- site, C4- is bonded to three equivalent Zr4+ and three equivalent Al3+ atoms to form CZr3Al3 octahedra that share corners with three equivalent CZr6 octahedra, corners with three equivalent CAl5 trigonal bipyramids, and edges with nine CZr3Al3 octahedra. The corner-sharing octahedral tilt angles are 2°. In the sixth C4- site, C4- is bonded to six Zr4+ atoms to form a mixture of corner and edge-sharing CZr6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°.
Zr3Al3C5 crystallizes in the hexagonal P6_3/mmc space group. The structure is two-dimensional and consists of two AlC sheets oriented in the (0, 0, 1) direction and two Zr3(AlC2)2 sheets oriented in the (0, 0, 1) direction. In each AlC sheet, Al3+ is bonded in a trigonal planar geometry to three equivalent C4- atoms. All Al–C bond lengths are 1.91 Å. C4- is bonded in a trigonal planar geometry to three equivalent Al3+ atoms. In each Zr3(AlC2)2 sheet, there are two inequivalent Zr+3.67+ sites. In the first Zr+3.67+ site, Zr+3.67+ is bonded to six equivalent C4- atoms to form a mixture of corner and edge-sharing ZrC6 octahedra. The corner-sharing octahedral tilt angles are 3°. All Zr–C bond lengths are 2.37 Å. In the second Zr+3.67+ site, Zr+3.67+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing ZrC6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are three shorter (2.29 Å) and three longer (2.59 Å) Zr–C bond lengths. Al3+ is bonded in a trigonal non-coplanar geometry to three equivalent C4- atoms. All Al–C bond lengths are 2.09 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded in a 3-coordinate geometry to three equivalent Zr+3.67+ and three equivalent Al3+ atoms. In the second C4- site, C4- is bonded to six Zr+3.67+ atoms to form a mixture of corner and edge-sharing CZr6 octahedra. The corner-sharing octahedral tilt angles are 0°.
Zr3Al3C5 crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. there are three inequivalent Zr+3.67+ sites. In the first Zr+3.67+ site, Zr+3.67+ is bonded to six C4- atoms to form ZrC6 octahedra that share corners with three equivalent ZrC6 octahedra, corners with three equivalent AlC4 tetrahedra, edges with nine ZrC6 octahedra, and edges with three equivalent AlC4 tetrahedra. The corner-sharing octahedral tilt angles are 3°. There are three shorter (2.32 Å) and three longer (2.50 Å) Zr–C bond lengths. In the second Zr+3.67+ site, Zr+3.67+ is bonded to six C4- atoms to form ZrC6 octahedra that share corners with three equivalent ZrC6 octahedra, corners with three equivalent AlC4 tetrahedra, edges with nine ZrC6 octahedra, and edges with three equivalent AlC4 tetrahedra. The corner-sharing octahedral tilt angles are 3°. There are three shorter (2.31 Å) and three longer (2.50 Å) Zr–C bond lengths. In the third Zr+3.67+ site, Zr+3.67+ is bonded to six C4- atoms to form a mixture of edge and corner-sharing ZrC6 octahedra. The corner-sharing octahedral tilt angles are 3°. All Zr–C bond lengths are 2.39 Å. There are three inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded in a trigonal planar geometry to three equivalent C4- atoms. All Al–C bond lengths are 1.94 Å. In the second Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent ZrC6 octahedra, corners with seven AlC4 tetrahedra, and edges with three equivalent ZrC6 octahedra. The corner-sharing octahedral tilt angles are 20°. There are one shorter (2.02 Å) and three longer (2.06 Å) Al–C bond lengths. In the third Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent ZrC6 octahedra, corners with seven AlC4 tetrahedra, and edges with three equivalent ZrC6 octahedra. The corner-sharing octahedral tilt angles are 20°. There are one shorter (2.02 Å) and three longer (2.06 Å) Al–C bond lengths. There are five inequivalent C4- sites. In the first C4- site, C4- is bonded to six Zr+3.67+ atoms to form a mixture of edge and corner-sharing CZr6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second C4- site, C4- is bonded to six Zr+3.67+ atoms to form a mixture of edge and corner-sharing CZr6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third C4- site, C4- is bonded in a 6-coordinate geometry to three equivalent Zr+3.67+ and three equivalent Al3+ atoms. In the fourth C4- site, C4- is bonded in a 6-coordinate geometry to three equivalent Zr+3.67+ and three equivalent Al3+ atoms. In the fifth C4- site, C4- is bonded to five Al3+ atoms to form corner-sharing CAl5 trigonal bipyramids.
Zr2Al3C5 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Zr4+ is bonded to six C+3.40- atoms to form ZrC6 octahedra that share corners with three equivalent ZrC6 octahedra, corners with three equivalent AlC6 octahedra, edges with three equivalent AlC6 octahedra, and edges with nine equivalent ZrC6 octahedra. The corner-sharing octahedra tilt angles range from 0–11°. There are three shorter (2.33 Å) and three longer (2.36 Å) Zr–C bond lengths. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six C+3.40- atoms to form distorted AlC6 octahedra that share corners with three equivalent ZrC6 octahedra, corners with three equivalent CAl6C pentagonal bipyramids, edges with three equivalent ZrC6 octahedra, and edges with six equivalent AlC6 octahedra. The corner-sharing octahedral tilt angles are 11°. There are three shorter (2.10 Å) and three longer (2.47 Å) Al–C bond lengths. In the second Al3+ site, Al3+ is bonded in a 6-coordinate geometry to six equivalent C+3.40- atoms. All Al–C bond lengths are 2.04 Å. There are three inequivalent C+3.40- sites. In the first C+3.40- site, C+3.40- is bonded to six Al3+ and one C+3.40- atom to form distorted CAl6C pentagonal bipyramids that share corners with three equivalent AlC6 octahedra, corners with three equivalent CZr3Al3 octahedra, corners with six equivalent CAl6C pentagonal bipyramids, edges with three equivalent CZr3Al3 octahedra, edges with six equivalent CAl6C pentagonal bipyramids, and a faceface with one CAl6C pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 14–49°. The C–C bond length is 1.59 Å. In the second C+3.40- site, C+3.40- is bonded to three equivalent Zr4+ and three equivalent Al3+ atoms to form CZr3Al3 octahedra that share corners with three equivalent CZr6 octahedra, corners with three equivalent CAl6C pentagonal bipyramids, edges with nine CZr3Al3 octahedra, and edges with three equivalent CAl6C pentagonal bipyramids. The corner-sharing octahedral tilt angles are 1°. In the third C+3.40- site, C+3.40- is bonded to six equivalent Zr4+ atoms to form a mixture of edge and corner-sharing CZr6 octahedra. The corner-sharing octahedral tilt angles are 1°.
Zr2Al4C5 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are two inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded to six C4- atoms to form ZrC6 octahedra that share corners with three equivalent ZrC6 octahedra, corners with three equivalent AlC4 tetrahedra, edges with nine ZrC6 octahedra, and edges with three equivalent AlC4 tetrahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.37 Å) and three longer (2.40 Å) Zr–C bond lengths. In the second Zr4+ site, Zr4+ is bonded to six C4- atoms to form ZrC6 octahedra that share corners with three equivalent ZrC6 octahedra, corners with three equivalent AlC4 tetrahedra, edges with nine ZrC6 octahedra, and edges with three equivalent AlC4 tetrahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.37 Å) and three longer (2.40 Å) Zr–C bond lengths. There are four inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four C4- atoms to form a mixture of edge and corner-sharing AlC4 trigonal pyramids. There are three shorter (1.96 Å) and one longer (2.19 Å) Al–C bond lengths. In the second Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent ZrC6 octahedra, corners with six equivalent AlC4 tetrahedra, corners with four AlC4 trigonal pyramids, and edges with three equivalent ZrC6 octahedra. The corner-sharing octahedral tilt angles are 11°. There are one shorter (1.95 Å) and three longer (2.14 Å) Al–C bond lengths. In the third Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent ZrC6 octahedra, corners with six equivalent AlC4 tetrahedra, corners with four AlC4 trigonal pyramids, and edges with three equivalent ZrC6 octahedra. The corner-sharing octahedral tilt angles are 11°. There are one shorter (1.95 Å) and three longer (2.13 Å) Al–C bond lengths. In the fourth Al3+ site, Al3+ is bonded to four C4- atoms to form a mixture of edge and corner-sharing AlC4 trigonal pyramids. There are three shorter (1.97 Å) and one longer (2.18 Å) Al–C bond lengths. There are five inequivalent C4- sites. In the first C4- site, C4- is bonded to three equivalent Zr4+ and three equivalent Al3+ atoms to form CZr3Al3 octahedra that share corners with three equivalent CZr6 octahedra, corners with three equivalent CAl5 trigonal bipyramids, and edges with nine CZr3Al3 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second C4- site, C4- is bonded to five Al3+ atoms to form CAl5 trigonal bipyramids that share corners with three equivalent CZr3Al3 octahedra, corners with six equivalent CAl5 trigonal bipyramids, and edges with three equivalent CAl5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 65°. In the third C4- site, C4- is bonded to six Zr4+ atoms to form a mixture of edge and corner-sharing CZr6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the fourth C4- site, C4- is bonded to five Al3+ atoms to form CAl5 trigonal bipyramids that share corners with three equivalent CZr3Al3 octahedra, corners with six equivalent CAl5 trigonal bipyramids, and edges with three equivalent CAl5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 65°. In the fifth C4- site, C4- is bonded to three equivalent Zr4+ and three equivalent Al3+ atoms to form CZr3Al3 octahedra that share corners with three equivalent CZr6 octahedra, corners with three equivalent CAl5 trigonal bipyramids, and edges with nine CZr6 octahedra. The corner-sharing octahedral tilt angles are 1°.
Zr5Al3C crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. there are two inequivalent Zr sites. In the first Zr site, Zr is bonded in a 8-coordinate geometry to two equivalent Zr and six equivalent Al atoms. Both Zr–Zr bond lengths are 2.81 Å. All Zr–Al bond lengths are 2.91 Å. In the second Zr site, Zr is bonded in a 7-coordinate geometry to five equivalent Al and two equivalent C atoms. There are a spread of Zr–Al bond distances ranging from 2.90–3.17 Å. Both Zr–C bond lengths are 2.34 Å. Al is bonded in a 9-coordinate geometry to nine Zr atoms. C is bonded to six equivalent Zr atoms to form face-sharing CZr6 octahedra.
Zr(AlC)4 crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. there are two inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded to six C4- atoms to form ZrC6 octahedra that share corners with three equivalent ZrC6 octahedra, corners with three equivalent AlC4 tetrahedra, edges with nine ZrC6 octahedra, and edges with three equivalent AlC4 tetrahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.37 Å) and three longer (2.39 Å) Zr–C bond lengths. In the second Zr4+ site, Zr4+ is bonded to six C4- atoms to form ZrC6 octahedra that share corners with three equivalent ZrC6 octahedra, corners with three equivalent AlC4 tetrahedra, edges with nine ZrC6 octahedra, and edges with three equivalent AlC4 tetrahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.37 Å) and three longer (2.39 Å) Zr–C bond lengths. There are eight inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four C4- atoms to form a mixture of edge and corner-sharing AlC4 tetrahedra. There are one shorter (1.94 Å) and three longer (2.18 Å) Al–C bond lengths. In the second Al3+ site, Al3+ is bonded to four C4- atoms to form a mixture of edge and corner-sharing AlC4 tetrahedra. There are one shorter (1.94 Å) and three longer (2.18 Å) Al–C bond lengths. In the third Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent ZrC6 octahedra, corners with six equivalent AlC4 tetrahedra, corners with four AlC4 trigonal pyramids, and edges with three equivalent ZrC6 octahedra. The corner-sharing octahedral tilt angles are 11°. There are one shorter (1.95 Å) and three longer (2.13 Å) Al–C bond lengths. In the fourth Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent ZrC6 octahedra, corners with six equivalent AlC4 tetrahedra, corners with four AlC4 trigonal pyramids, and edges with three equivalent ZrC6 octahedra. The corner-sharing octahedral tilt angles are 11°. There are one shorter (1.95 Å) and three longer (2.13 Å) Al–C bond lengths. In the fifth Al3+ site, Al3+ is bonded to four C4- atoms to form a mixture of distorted edge and corner-sharing AlC4 trigonal pyramids. There are three shorter (1.97 Å) and one longer (2.17 Å) Al–C bond lengths. In the sixth Al3+ site, Al3+ is bonded to four C4- atoms to form a mixture of edge and corner-sharing AlC4 trigonal pyramids. There are three shorter (1.97 Å) and one longer (2.16 Å) Al–C bond lengths. In the seventh Al3+ site, Al3+ is bonded to four C4- atoms to form a mixture of edge and corner-sharing AlC4 trigonal pyramids. There are three shorter (1.96 Å) and one longer (2.21 Å) Al–C bond lengths. In the eighth Al3+ site, Al3+ is bonded to four C4- atoms to form a mixture of edge and corner-sharing AlC4 trigonal pyramids. There are three shorter (1.96 Å) and one longer (2.20 Å) Al–C bond lengths. There are eight inequivalent C4- sites. In the first C4- site, C4- is bonded to six Al3+ atoms to form CAl6 octahedra that share corners with six CAl5 trigonal bipyramids and edges with six equivalent CAl6 octahedra. In the second C4- site, C4- is bonded to five Al3+ atoms to form CAl5 trigonal bipyramids that share corners with three equivalent CZr3Al3 octahedra, corners with six equivalent CAl5 trigonal bipyramids, and edges with three equivalent CAl5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 65°. In the third C4- site, C4- is bonded to six Zr4+ atoms to form a mixture of edge and corner-sharing CZr6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the fourth C4- site, C4- is bonded to five Al3+ atoms to form CAl5 trigonal bipyramids that share corners with three equivalent CAl6 octahedra, corners with six equivalent CAl5 trigonal bipyramids, and edges with three equivalent CAl5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 63°. In the fifth C4- site, C4- is bonded to five Al3+ atoms to form CAl5 trigonal bipyramids that share corners with three equivalent CZr3Al3 octahedra, corners with six equivalent CAl5 trigonal bipyramids, and edges with three equivalent CAl5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 65°. In the sixth C4- site, C4- is bonded to three equivalent Zr4+ and three equivalent Al3+ atoms to form CZr3Al3 octahedra that share corners with three equivalent CZr6 octahedra, corners with three equivalent CAl5 trigonal bipyramids, and edges with nine CZr6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the seventh C4- site, C4- is bonded to three equivalent Zr4+ and three equivalent Al3+ atoms to form CZr3Al3 octahedra that share corners with three equivalent CZr6 octahedra, corners with three equivalent CAl5 trigonal bipyramids, and edges with nine CZr3Al3 octahedra. The corner-sharing octahedral tilt angles are 1°. In the eighth C4- site, C4- is bonded to five Al3+ atoms to form distorted CAl5 trigonal bipyramids that share corners with three equivalent CAl6 octahedra, corners with six equivalent CAl5 trigonal bipyramids, and edges with three equivalent CAl5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 62°.
Zr2Al3C4 crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of one Zr2Al2C3 sheet oriented in the (0, 0, 1) direction and one Zr2Al4C5 sheet oriented in the (0, 0, 1) direction. In the Zr2Al2C3 sheet, Zr+3.50+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing ZrC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.31 Å) and three longer (2.53 Å) Zr–C bond lengths. Al3+ is bonded in a trigonal non-coplanar geometry to three equivalent C4- atoms. All Al–C bond lengths are 2.01 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded to six equivalent Zr+3.50+ atoms to form edge-sharing CZr6 octahedra. In the second C4- site, C4- is bonded in a 6-coordinate geometry to three equivalent Zr+3.50+ and three equivalent Al3+ atoms. In the Zr2Al4C5 sheet, Zr+3.50+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing ZrC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.34 Å) and three longer (2.39 Å) Zr–C bond lengths. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded in a trigonal planar geometry to three equivalent C4- atoms. All Al–C bond lengths are 1.95 Å. In the second Al3+ site, Al3+ is bonded in a 3-coordinate geometry to six C4- atoms. There are three shorter (2.11 Å) and three longer (2.58 Å) Al–C bond lengths. There are three inequivalent C4- sites. In the first C4- site, C4- is bonded to six equivalent Zr+3.50+ atoms to form CZr6 octahedra that share corners with six equivalent CZr3Al3 octahedra and edges with twelve CZr6 octahedra. The corner-sharing octahedral tilt angles are 2°. In the second C4- site, C4- is bonded to three equivalent Zr+3.50+ and three equivalent Al3+ atoms to form a mixture of corner and edge-sharing CZr3Al3 octahedra. The corner-sharing octahedral tilt angles are 2°. In the third C4- site, C4- is bonded in a distorted trigonal planar geometry to six Al3+ atoms.