The potential energy curves for the X1Σ g+, B1△g and B′1Σ g+ states of C2 have been studied by using MRC and approximate CI methods, and are benchmarked against the calculations of full configuration in teraction (FCI). The results obtained by MRCI method agree with the FCI very well, and even are accu rate enough to compare other approximate methods as benchmark, when the calculations of FCI ar not feasible. The approximate CI methods mentioned in this paper are reliable for treating chemica problems.
LI AnYang1, WANG YuBin2, DOU YuSheng1,3 & WEN ZhenYi1,2 1 Institute of Bio-information, Chongqing University of Post and Telecommunication, Chongqing 400065, China
1,3-dimethyl-2-ferrocenylmethylbenzimidazole(a) is a novel benzimidazole complex.Based on the X-ray structure,the quantum chemical calculation was performed.This compound belongs to doublet system,and full geometry optimizations were carried out with ab initio restrict open-shell method ROHF.For this initialized structure,B3LYP and B3PW91 methods were used to re-optimize.Results of B3PW91 are better accordance with the experiments,so they were used to the later calculations,such as,energy,frontier molecular orbital components and net charges distribution etc.It is concluded that the complex is stable and the active sites are on Fe,C11 and C12 atoms.
The potential energy surfaces for the nine low-lying electronic states of SO2 have been constructed by using the multi-reference second order perturbation theory (MRPT2) with the basis set cc-pVTZ. The optimized geometries and the adiabatic excitation energies of these states are in good agreement with experiments and previous calculations. The crossings and avoided crossings dis- played in the potential energy surfaces are expounded.
LI Anyang1, SUO Bing2, WEN Zhenyi2 & WANG Yubin2 1. Shanxi Key Laboratory of Physico-inorganic Chemistry, Department of Chemistry, Northwest University, Xi’an 710069, China
