用准简并微扰理论研究锰二聚体的基态。

A study of the ground state of manganese dimer using quasidegenerate perturbation theory.

作者信息

Yamamoto Shigeyoshi, Tatewaki Hiroshi, Moriyama Hiroko, Nakano Haruyuki

机构信息

Faculty of Liberal Arts, Chukyo University, 101-2 Yagoto-Honmachi, Showa-ku, Nagoya, Aichi 466-8666, Japan.

出版信息

J Chem Phys. 2006 Mar 28;124(12):124302. doi: 10.1063/1.2178798.

DOI:10.1063/1.2178798

PMID:16599669

Abstract

We study the electronic structure of the ground state of the manganese dimer using the state-averaged complete active space self-consistent field method, followed by second-order quasidegenerate perturbation theory. Overall potential energy curves are calculated for the 1Sigmag+, 11Sigmau+, and 11Piu states, which are candidates for the ground state. Of these states, the 1Sigmag+ state has the lowest energy and we therefore identify it as the ground state. We find values of 3.29 A, 0.14 eV, and 53.46 cm(-1) for the bond length, dissociation energy, and vibrational frequency, in good agreement with the observed values of 3.4 A, 0.1 eV, and 68.1 cm(-1) in rare-gas matrices. These values show that the manganese dimer is a van der Waals molecule with antiferromagnetic coupling.

摘要

我们使用态平均完全活性空间自洽场方法，随后采用二阶准简并微扰理论，研究了锰二聚体基态的电子结构。计算了作为基态候选态的(1\Sigma_g^+)、(1^1\Sigma_u^+)和(1^1\pi_u)态的整体势能曲线。在这些态中，(1\Sigma_g^+)态能量最低，因此我们将其确定为基态。我们得到键长为(3.29 Å)、解离能为(0.14 eV)、振动频率为(53.46 cm^{-1})，与稀有气体基质中观测到的(3.4 Å)、(0.1 eV)和(68.1 cm^{-1})值吻合良好。这些值表明锰二聚体是具有反铁磁耦合的范德瓦尔斯分子。