The experimental photoelectron spectra of di- and triatomic copper oxide anions have been reported previously. We present an analysis of the experimental spectra of the CuO^–, Cu₂O^–, and CuO₂^– anions using equation-of-motion coupled-cluster (EOM-CC) methods. The open-shell electronic structure of each molecule demands a unique combination of EOM-CC methods to achieve an accurate and balanced representation of the multiconfigurational anionic- and neutral-state manifolds. Analysis of the Dyson orbitals associated with photodetachment from CuO^– reveals the strong non-Koopmans character of the CuO states. For the lowest detachment energy, a good agreement between theoretical and experimental values is obtained with CCSD(T) (coupled-cluster with single and double excitations and perturbative account of triple excitations). The (T) correction is particularly important for Cu₂O^–. Use of a relativistic pseudopotential and matching basis set improves the quality of results in most cases. EOM-DIP-CCSD analysis of the low-lying states of CuO₂^– reveals multiple singlet and triplet anionic states near the triplet ground state, adding an extra layer of complexity to the interpretation of the experimental CuO₂^– photoelectron spectrum.

中文翻译：

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用运动方程耦合簇方法模拟CuO，Cu ₂ O和CuO ₂阴离子的光电子能谱：在Fock空间中的一次冒险

先前已经报道了二原子和三原子氧化铜阴离子的实验光电子能谱。我们使用运动方程耦合簇（EOM-CC）方法对CuO ^–，Cu ₂ O ^–和CuO ₂ ^–阴离子的实验光谱进行了分析。每个分子的开壳电子结构需要EOM-CC方法的独特组合，以实现多构型阴离子和中性态歧管的准确平衡的表示。与CuO光解离有关的戴森轨道的分析^–揭示了CuO州强大的非考夫曼性格。对于最低的脱离能，使用CCSD（T）（具有单激励和双激励的耦合集群以及三激励的扰动帐户）可以在理论值和实验值之间取得良好的一致性。（T）校正对于Cu ₂ O ^–尤其重要。在大多数情况下，使用相对论的伪势和匹配基础集可以提高结果的质量。CuO的低洼状态的EOM-DIP-CCSD分析₂ ^-揭示了多个单态和靠近三重基态三重态阴离子，增加复杂性的额外层的实验CuO的解释₂ ^-光电子光谱。