Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (7): 2218.doi: 10.7503/cjcu20210119

• Article • Previous Articles     Next Articles

λ-DFCAS: A Hybrid Density Functional Complete Active Space Self Consistent Field Method

YING Fuming, JI Chenru, SU Peifeng, WU Wei()   

  1. State Key Laboratory of Physical Chemistry of Solid Surfaces,Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry,Chemistry and Chemical Engineering College,Xiamen University,Xiamen 361005,China
  • Received:2021-02-26 Online:2021-07-10 Published:2021-04-12
  • Contact: WU Wei E-mail:weiwu@xmu.edu.cn
  • Supported by:
    This paper is supported by the National Natural Science Foundation of China(21733008)

Abstract:

A multireference density functional theory method, named λ-DFCAS, is presented in this paper. Based on the strategy used in λ-DFVB method, the λ-DFCAS method divides electronic correlation into two parts: the static correlation is covered by multi-reference wave function method, complete active space self-consistent field(CASSCF), while the dynamic correlation is provided by Kohn-Sham density functional theory(KS-DFT). The parameter λ in λ-DFCAS, controlling the hybrid extent of dynamic and static correlations, varies according to the multireference character of a given molecular system. The λ-DFCAS method provides a multireference density functional theory with size-consistency. Test examples show that the accuracy of λ-DFCAS is close to the complete active space second perturbation theory(CASPT2) method, while its computational cost is roughly the same as CASSCF.

Key words: Complete active space self-consistent field(CASSCF), Density functional theory(DFT), Multireference, Electronic correlation

CLC Number: 

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