A multireference perturbation theory study on the Fe2 molecule: in quest of the ground state

被引：22

作者：

Angeli, Celestino ^{[1
]}

Cimiraglia, Renzo ^{[1
]}

机构：

[1] Univ Ferrara, Dipartmento Chim, I-44100 Ferrara, Italy

来源：

MOLECULAR PHYSICS | 2011年 / 109卷 / 11期

关键词：

iron dimer (Fe-2); multireference perturbation theory; NEVPT; transition metal dimers; ELECTRONIC-STRUCTURE; DISSOCIATION ENERGY; IRON; SPIN; DIATOMICS; FE2;

D O I：

10.1080/00268976.2011.566586

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The (9)Sigma(g) and (7)Delta(u) states of the iron dimer, which according to a long-standing debate are the most probable candidates for the assignment of the ground state, have been investigated within the frame of multireference perturbation theory (PC-NEVPT2 and SC-NEVPT3) up to the third order in the energy. At short internuclear distances the (7)Delta(u) state originates from the interaction of a ground-state D-5 Fe atom with an excited-state F-5, whereas at large distances it results from the van der Waals interaction of two D-5 atoms. At all levels of calculation the (9)Sigma(-)(g) term appears to have lower energy than the short-range (7)Delta(u) state and can thus be assigned as the ground state of the iron dimer. The spectroscopic constants of the (9)Sigma(-)(g) state (R-e = 2.164 angstrom, omega(e) = 302.6 cm(-1) at the SC-NEVPT3 level of approximation) are in good accordance with the other high level ab initio calculation published thus far.

引用

页码：1503 / 1509

页数：7