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Crystal structure of the layered arsenide Rb3Cu3As2
Alexander Ovchinnikov1, Hua He1, Svilen Bobev1
1Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA.
Abstract:
The crystal structure of a new arsenide, Rb3Cu3As2 (trirubidium tricopper diarsenide), has been established from single-crystal X-ray diffraction data. This compound crystallizes in the K3Cu3P2 type, with layers of interlinked CuAs2 units. The partitioning of the available valence electrons yields the charge-balanced composition (Rb+)3(Cu+)3(As3-)2, placing this phase in a broad field of transition-metal-containing Zintl phases. First-principles calculations confirm a semiconducting ground state, in accordance with electron-counting considerations. Chemical bonding analysis reveals strong covalent Cu-As bonds and ionic Rb...As interactions. In addition, a weak attraction is found between the Cu atoms, possibly pointing toward cuprophilic interactions.
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