Materials Data on HfU(TaC2)2 by Materials Project

UHf(TaC2)2 is alpha Po-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. U4+ is bonded to six C4- atoms to form UC6 octahedra that share corners with three equivalent HfC6 octahedra, corners with three equivalent TaC6 octahedra, edges with three equivalent HfC6 octahedra, edges with three equivalent TaC6 octahedra, and edges with six equivalent UC6 octahedra. The corner-sharing octahedra tilt angles range from 3–7°. There are three shorter (2.42 Å) and three longer (2.45 Å) U–C bond lengths. Hf4+ is bonded to six C4- atoms to form HfC6 octahedra that share corners with three equivalent UC6 octahedra, corners with three equivalent TaC6 octahedra, edges with three equivalent UC6 octahedra, edges with three equivalent TaC6 octahedra, and edges with six equivalent HfC6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are three shorter (2.31 Å) and three longer (2.32 Å) Hf–C bond lengths. There are two inequivalent Ta4+ sites. In the first Ta4+ site, Ta4+ is bonded to six C4- atoms to form TaC6 octahedra that share corners with three equivalent UC6 octahedra, corners with three equivalent TaC6 octahedra, edges with three equivalent UC6 octahedra, and edges with nine TaC6 octahedra. The corner-sharing octahedra tilt angles range from 1–7°. There are three shorter (2.23 Å) and three longer (2.28 Å) Ta–C bond lengths. In the second Ta4+ site, Ta4+ is bonded to six C4- atoms to form TaC6 octahedra that share corners with three equivalent HfC6 octahedra, corners with three equivalent TaC6 octahedra, edges with three equivalent HfC6 octahedra, and edges with nine TaC6 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. There are three shorter (2.24 Å) and three longer (2.26 Å) Ta–C bond lengths. There are four inequivalent C4- sites. In the first C4- site, C4- is bonded to six Ta4+ atoms to form CTa6 octahedra that share corners with six CHf3Ta3 octahedra and edges with twelve CTa6 octahedra. The corner-sharing octahedra tilt angles range from 1–2°. In the second C4- site, C4- is bonded to three equivalent Hf4+ and three equivalent Ta4+ atoms to form a mixture of edge and corner-sharing CHf3Ta3 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the third C4- site, C4- is bonded to three equivalent U4+ and three equivalent Hf4+ atoms to form a mixture of edge and corner-sharing CHf3U3 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the fourth C4- site, C4- is bonded to three equivalent U4+ and three equivalent Ta4+ atoms to form a mixture of edge and corner-sharing CU3Ta3 octahedra. The corner-sharing octahedra tilt angles range from 1–2°.

UHf(TaC₂)₂为α-钋（α-Po）衍生结构，结晶于三方晶系R3m空间群，整体为三维晶体结构。U⁴+与六个C⁴-原子配位形成UC₆八面体，该八面体分别与三个等价HfC₆八面体共享顶点、与三个等价TaC₆八面体共享顶点，同时与三个等价HfC₆八面体共享棱、与三个等价TaC₆八面体共享棱，还与六个等价UC₆八面体共享棱。共顶点八面体的倾斜角范围为3°~7°。U-C键存在三组较短键长（2.42 Å）与三组较长键长（2.45 Å）。Hf⁴+与六个C⁴-原子配位形成HfC₆八面体，该八面体分别与三个等价UC₆八面体共享顶点、与三个等价TaC₆八面体共享顶点，同时与三个等价UC₆八面体共享棱、与三个等价TaC₆八面体共享棱，还与六个等价HfC₆八面体共享棱。共顶点八面体的倾斜角为3°。Hf-C键存在三组较短键长（2.31 Å）与三组较长键长（2.32 Å）。体系中存在两个不等价的Ta⁴+位点。在第一类Ta⁴+位点中，Ta⁴+与六个C⁴-原子配位形成TaC₆八面体，该八面体分别与三个等价UC₆八面体共享顶点、与三个等价TaC₆八面体共享顶点，同时与三个等价UC₆八面体共享棱、与九个等价TaC₆八面体共享棱。共顶点八面体的倾斜角范围为1°~7°。Ta-C键存在三组较短键长（2.23 Å）与三组较长键长（2.28 Å）。在第二类Ta⁴+位点中，Ta⁴+与六个C⁴-原子配位形成TaC₆八面体，该八面体分别与三个等价HfC₆八面体共享顶点、与三个等价TaC₆八面体共享顶点，同时与三个等价HfC₆八面体共享棱、与九个等价TaC₆八面体共享棱。共顶点八面体的倾斜角范围为1°~3°。Ta-C键存在三组较短键长（2.24 Å）与三组较长键长（2.26 Å）。体系中存在四个不等价的C⁴-位点。在第一类C⁴-位点中，C⁴-与六个Ta⁴+原子配位形成CTa₆八面体，该八面体与六个CHf₃Ta₃八面体共享顶点，同时与十二个CTa₆八面体共享棱。共顶点八面体的倾斜角范围为1°~2°。在第二类C⁴-位点中，C⁴-与三个等价Hf⁴+和三个等价Ta⁴+原子配位，形成兼具棱共享与顶点共享的CHf₃Ta₃八面体。共顶点八面体的倾斜角范围为0°~1°。在第三类C⁴-位点中，C⁴-与三个等价U⁴+和三个等价Hf⁴+原子配位，形成兼具棱共享与顶点共享的CHf₃U₃八面体。共顶点八面体的倾斜角范围为0°~1°。在第四类C⁴-位点中，C⁴-与三个等价U⁴+和三个等价Ta⁴+原子配位，形成兼具棱共享与顶点共享的CU₃Ta₃八面体。共顶点八面体的倾斜角范围为1°~2°。