The electronic structure of nitrogen trifluoride was investigated by combining the high-resolution electron momentum spectroscopy with the high-level calculations. The experimental binding energy spectra and the momen...The electronic structure of nitrogen trifluoride was investigated by combining the high-resolution electron momentum spectroscopy with the high-level calculations. The experimental binding energy spectra and the momentum distributions of each orbital were compared with the results of Hartree-Fock, density functional theory （DFT）, and symmetry-adapted- cluster configuration-interaction （SAC-CI） methods. SAC-CI and DFT-B3LYP with the aug-cc-pVTZ basis set can well reproduce the binding energy spectra and the observed momentum distributions of the valence orbitals except 1 a2 and 4e orbitals. It was found that the calculated momentum distributions using DFT-B3LYP are even better than those using the high-level SAC-CI method.展开更多
This paper applies the symmetry-aziapted-cluster/symmetry-adapted-cluster configuration-interaction （SAC/SACCI） method to optimize the structures for X^1∑^＋, A^1 Ⅱ and C^1 ∑^- states of SiO molecule with the bas...This paper applies the symmetry-aziapted-cluster/symmetry-adapted-cluster configuration-interaction （SAC/SACCI） method to optimize the structures for X^1∑^＋, A^1 Ⅱ and C^1 ∑^- states of SiO molecule with the basis sets D95＋＋, 6-311＋＋G and 6-311＋＋G^＊＊. Comparing the obtained results with the experiments, it gets the conclusion that the basis set 6-311＋＋G^＊＊ is most suitable for the optimal structure calculations of X^1.∑^＋, A^Ⅱ and C^1∑^- states of SiO molecule. The whole potential energy curves for these electronic states are further scanned by using SAC/6-311＋＋G^＊＊ method for the ground state and SAC-CI/6-311＋＋G^＊＊ method for the excited states, then use a least square method to fit Murrell^Sorbie functions, at last the spectroscopic constants and force constants are calculated, which are in good agreement with the experimental data.展开更多
采用单双激发运动方程耦合簇(EOM-CCSD)以及多个包含迭代三激发在内的运动方程耦合簇变体(EOM-CCSDT-i,i=1a,1b,2,3和EOM-CC3)计算了HOF价层垂直电离势(VIP).在EOM-CCSD水平上优化出各价层电离态结构,得到绝热电离势(AIP),进一步计算出...采用单双激发运动方程耦合簇(EOM-CCSD)以及多个包含迭代三激发在内的运动方程耦合簇变体(EOM-CCSDT-i,i=1a,1b,2,3和EOM-CC3)计算了HOF价层垂直电离势(VIP).在EOM-CCSD水平上优化出各价层电离态结构,得到绝热电离势(AIP),进一步计算出谐振频率.同时对称匹配簇组态相互作用(SAC/SAC-CI)也被应用到部分计算.结果显示:EOM-CC3、EOM-CCSDT-3计算的VIP接近于全三激发运动方程耦合簇EOM-CCSDT结果;EOM-CC与SAC-CI值基本一致;同时发现HOF光电子能谱实验在2A'态指认上有误并重新进行归属.HOF的第三VIP应为16.9 e V,而非光电子能谱实验测得的16.0 e V.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.11174175)the Tsinghua University Initiative Scientific Research Program,China
文摘The electronic structure of nitrogen trifluoride was investigated by combining the high-resolution electron momentum spectroscopy with the high-level calculations. The experimental binding energy spectra and the momentum distributions of each orbital were compared with the results of Hartree-Fock, density functional theory （DFT）, and symmetry-adapted- cluster configuration-interaction （SAC-CI） methods. SAC-CI and DFT-B3LYP with the aug-cc-pVTZ basis set can well reproduce the binding energy spectra and the observed momentum distributions of the valence orbitals except 1 a2 and 4e orbitals. It was found that the calculated momentum distributions using DFT-B3LYP are even better than those using the high-level SAC-CI method.
基金Project supported by the Basic Research Program of Education Bureau of Henan Province of China (Grant No 2008A140006)
文摘This paper applies the symmetry-aziapted-cluster/symmetry-adapted-cluster configuration-interaction （SAC/SACCI） method to optimize the structures for X^1∑^＋, A^1 Ⅱ and C^1 ∑^- states of SiO molecule with the basis sets D95＋＋, 6-311＋＋G and 6-311＋＋G^＊＊. Comparing the obtained results with the experiments, it gets the conclusion that the basis set 6-311＋＋G^＊＊ is most suitable for the optimal structure calculations of X^1.∑^＋, A^Ⅱ and C^1∑^- states of SiO molecule. The whole potential energy curves for these electronic states are further scanned by using SAC/6-311＋＋G^＊＊ method for the ground state and SAC-CI/6-311＋＋G^＊＊ method for the excited states, then use a least square method to fit Murrell^Sorbie functions, at last the spectroscopic constants and force constants are calculated, which are in good agreement with the experimental data.
文摘采用单双激发运动方程耦合簇(EOM-CCSD)以及多个包含迭代三激发在内的运动方程耦合簇变体(EOM-CCSDT-i,i=1a,1b,2,3和EOM-CC3)计算了HOF价层垂直电离势(VIP).在EOM-CCSD水平上优化出各价层电离态结构,得到绝热电离势(AIP),进一步计算出谐振频率.同时对称匹配簇组态相互作用(SAC/SAC-CI)也被应用到部分计算.结果显示:EOM-CC3、EOM-CCSDT-3计算的VIP接近于全三激发运动方程耦合簇EOM-CCSDT结果;EOM-CC与SAC-CI值基本一致;同时发现HOF光电子能谱实验在2A'态指认上有误并重新进行归属.HOF的第三VIP应为16.9 e V,而非光电子能谱实验测得的16.0 e V.
