Transitions from Stable to Metastable States in the Cr2On and Cr2On– Series, n = 1–14

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• 作者：G. L. GutsevK. V. Bozhenko ; L. G. Gutsev ; A. N. Utenyshev ; S. M. Aldoshin
• 刊名：Journal of Physical Chemistry A
• 出版年：2017
• 出版时间：February 2, 2017
• 年：2017
• 卷：121
• 期：4
• 页码：845-854
• 全文大小：699K
• ISSN：1520-5215

文摘

The geometrical and electronic structures of the Cr₂O_n and Cr₂O_n^– clusters are computed using density functional theory with a generalized gradient approximation in the range of 1 ≤ n ≤ 14. Local total spin magnetic moments, polarizabilities, binding energies per atom, and energies of abstraction of O and O₂ are computed for both series along with electron affinities of the neutrals and vertical detachment energies of the anions. In the lowest total energies states of Cr₂O₂, Cr₂O₃, Cr₂O₄, Cr₂O₁₄, Cr₂O₃^–, Cr₂O₄^–, and Cr₂O₁₄^–, total spin magnetic moments of the Cr atoms are quite large and antiferromagnetically coupled. In the rest of the series, at least one of the Cr atoms has no spin-magnetic moment at all. The computed vertical electron-detachment energies of the Cr₂O_n^– are in good agreement with experimental values obtained in the 1 ≤ n ≤ 7 range. All neutral Cr₂O_n possess electron affinities larger than the electron affinities of halogen atoms when n > 6 and are thus superhalogens. It is found that the neutrals and anions are stable with respect to the abstraction of an O atom in the whole range of n considered, whereas both neutrals and anions became unstable toward the loss of O₂ for n > 7. The polarizability per atom decreases sharply when n moves from one to four and then remains nearly constant for larger n values in both series. The largest members in both series, Cr₂O₁₄ and Cr₂O₁₄^–, possess the geometrical structures of the Cr₂(O₂)₇ type by analogy with monochromium Cr(O₂)₄.