关于弱键合NO2二聚体（N2O4）激发态的多组态自洽场和多参考内收缩组态相互作用研究

Multiconfigurational self-consistent field and multireference internally contracted configuration interaction studies on the excited states of weakly bonded NO2 dimer (N2O4).

作者信息

Li Yumin

机构信息

Department of Chemistry, East Carolina University, Greenville, NC 27858, USA.

出版信息

J Chem Phys. 2007 Nov 28;127(20):204502. doi: 10.1063/1.2801982.

DOI:10.1063/1.2801982

PMID:18052437

Abstract

In this paper, the vertical excitation energies of total of 32 states of N(2)O(4) including the lowest two singlet states and two triplet states of each of the A(g), B(3u), B(2u), B(1g), B(1u), B(2g), B(3g), and A(u) symmetries were calculated at multiconfigurational self-consistent field (MCSCF) and the multireference internally contracted configuration interaction (MRCI) levels of theory on the active space (15o,16e) with aug-cc-pVDZ basis set. The potential energy curves of the eight singlet states(1 (1)A(g), 1 (1)B(3u), 1 (1)B(2u), 1 (1)B(1g), 1 (1)B(1u), 1 (1)B(2g), 1 (1)B(3g), and 1 (1)A(u)) and eight triplet states (1 (3)A(g), 1 (3)B(3u), 1 (3)B(2u), 1 (3)B(1g), 1 (3)B(1u), 1 (3)B(2g), 1 (3)B(3g), and 1 (3)A(u)) were calculated at MCSCF and MRCI levels of theory on the active space (15o,16e) with aug-cc-pVDZ basis set along the N-N distance. The vertical excitation energies of 1 (1)B(3u), 1 (1)B(2u), and 1 (1)B(1u) states with nonzero transition moment are 4.60 eV (269.6 nm), 6.06 eV (204.6 nm), and 7.71 eV (160.8 nm), respectively, at MRCI level of theory. The photodissociation asymptotics were assigned as NO(2)(X (2)A(1))+NO(2)(X (2)A(1)) for ground state 1 (1)A(g) and the 1 (3)B(1u) state, NO(2)(X (2)A(1))+NO(2)(1 (2)A(2)) for the 1 (1)B(1g), 1 (3)B(1g), 1 (1)A(u), and 1 (3)A(u) states, NO(2)(X (2)A(1))+NO(2)(1 (2)B(1)) for the 1 (1)B(3u), 1 (3)B(3u), 1 (1)B(2g), and 1 (3)B(2g) states, and NO(2)(X (2)A(1))+NO(2)(1 (2)B(2)) for the 1 (1)B(2u), 1 (3)B(2u), 1 (1)B(3g), and 1 (3)B(3g) states.

摘要

本文在多组态自洽场（MCSCF）和多参考内收缩组态相互作用（MRCI）理论水平下，使用aug-cc-pVDZ基组，在活性空间(15o,16e)中计算了N₂O₄总共32个态的垂直激发能，包括最低的两个单重态以及A(g)、B(3u)、B(2u)、B(1g)、B(1u)、B(2g)、B(3g)和A(u)对称性的每个对称态中的两个三重态。在MCSCF和MRCI理论水平下，使用aug-cc-pVDZ基组，沿着N-N距离计算了八个单重态（1¹A(g)、1¹B(3u)、1¹B(2u)、1¹B(1g)、1¹B(1u)、1¹B(2g)、1¹B(3g)和1¹A(u)）和八个三重态（1³A(g)、1³B(3u)、1³B(2u)、1³B(1g)、1³B(1u)、1³B(2g)、1³B(3g)和1³A(u)）的势能曲线。在MRCI理论水平下，具有非零跃迁矩的1¹B(3u)、1¹B(2u)和1¹B(1u)态的垂直激发能分别为4.60 eV（269.6 nm）、6.06 eV（204.6 nm）和7.71 eV（160.8 nm）。对于基态1¹A(g)和1³B(1u)态，光解离渐近线被指定为NO₂(X²A₁)+NO₂(X²A₁)；对于1¹B(1g)、1³B(1g)、1¹A(u)和1³A(u)态，为NO₂(X²A₁)+NO₂(1²A₂)；对于1¹B(3u)、1³B(3u)、1¹B(2g)和1³B(2g)态，为NO₂(X²A₁)+NO₂(1²B₁)；对于1¹B(2u)、1³B(2u)、1¹B(3g)和1³B(3g)态，为NO₂(X²A₁)+NO₂(1²B₂)。