Is the FeC3- cluster linear? Theoretical study of the equilibrium structure and bonding of FeC3-
- 化学化工－已发表论文 
Ab initio electron correlation methods, and density functional theory are used to investigate the structure, bonding, and stability of FeC3-. Theoretical calculations. show that the ground state of the FeC3- anion. strongly depends on the level of theory. The linear (4)Sigma(-) state with an open configuration delta(2)sigma(1) is predicted to be the ground state of FeC3- at the coupled-cluster theory restricted to single, double, and noniterative triple excitations (CCSD[T])//CISD and multireference (MR) second-order Moller-Plesset (MP2)//CAS self-consistent field (SCF) levels. Next stable conformations are a C-2V ring structure II (B-4(2)) and a C-2V structure III ((4)A(2)) in which Fe is bonded to one carbon atom of a triangular C-3. However, CISD and CCSD//CISD calculations show that the C-2V ring structure II and the C-2V structure, III are more slightly stable than is the linear structure I of FeC3-. The harmonic vibrational frequencies and relevant vertical electron binding energies are reported. Possible detachment transitions in the photoelectron spectrum of FeC3- are discussed on-the basis of current calculations. (C) 2003 Wiley Periodicals, Inc.