PdO0,±1, PdH0,±1及PdOH分子结构和电子性质的从头计算

利用多种从头计算方法对PdO0,±1, PdH0,±1以及PdOH的结构和电子性质进行了理论研究. 优化了PdO分子两个能量相近的态(3∏和3∑-), 结果表明PdO 的3∏态较3∑-态更为稳定, 在单双激发耦合簇理论(CCSD)水平下3∑-态的总能量比3∏态的高出0.286 eV. 在结构优化的基础上计算了PdO以及PdH的绝热电离能(AIE)和电子亲和能(AEA), 计算结果与实验值符合得很好. PdOH的基态为Cs对称性的角型结构Pd—OH(2A'态), 另外还优化得到两个2A'态的亚稳结构, 分别对应于Pd—OH和O—Pd—H, CCSD水平下两个亚稳态的总能量较基态分别高0.405和2.284 eV, 优化得到了连接这两个2A'态的过渡态, 并计算了相应的反应能垒.

Ab initio Investigation of the Structures and Electronic Properties of PdO0,±1, PdH0,±1 and PdOH Molecules

Several ab initio methods were employed to investigate the structures and electronic properties of PdO0,±1, PdH0,±1, and PdOH. Two states (3∏and 3∑-) with similar energies were found for PdO. Energetically, the 3∏ state is more favored compared to the 3∑- state. At the coupled-cluster method with single and double excitations (CCSD) level of theory, the 3∑- state is 0.286 eV higher in total energy than the 3∏state. Based on the favored structures, we calculated the adiabatic ionization energies (AIE) and electronic affinities (AEA) of the PdO and PdH molecules. Our calculated values of AIE and AEA are in good agreement with the available experimental values. Geometry optimization result showed the ground state of PdOH to be a non-linear Pd—OH (2A') structure with Cs symmetry. In addition, we obtained two metastable structures Pd—OH (2A') and O—Pd—H (2A'). We optimized the transition state connecting these two metastable states and calculated the corresponding energy barrier.