Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (7): 2210.doi: 10.7503/cjcu20210308

• Article • Previous Articles     Next Articles

Development and Benchmark of Lower Scaling Doubly Hybrid Density Functional XYG3

ZHENG Ruoxin, ZHANG Igor Ying(), XU Xin   

  1. Department of Chemistry,Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials,Key Laboratory of Computational Physical Sciences,Ministry of Education,Fudan University,Shanghai 200433,China
  • Received:2021-05-04 Online:2021-07-10 Published:2021-06-22
  • Contact: ZHANG Igor Ying E-mail:igor_zhangying@fudan.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21973015);the Science Challenge Project of China(TZ2018004)

Abstract:

Doubly hybrid density functional XYG3 is one of the most accurate density functional approximations currently available. XYG3 introduces the unoccupied orbital information in the form of the second-order perturbation theory(PT2), and therefore suffers the same computational costs as the standard PT2 method. The formal computational scaling of the canonical XYG3 is N to the fifth power[ON5], where N denotes the system size, and the memory consumption scales in the fourth power[ON4], which significantly limit the applicability of XYG3 to complex large systems. In this work, we introduce a local-scaling XYG3 method, LT-XYG3, which is based on the local variant of Resolution-of-Identity technique(RI-LVL) and the Laplace-Transformed PT2(LT-PT2). The use of an OpenMP/MPI hybrid parallel design guarantees the parallel efficiency of LT-XYG3 for different kinds of chemical environment. Systematic benchmark on a serial of water clusters with various system sizes and the ISOL22 test set demonstrates that LT-XYG3 holds the same accuracy as the canonical XYG3 and brings a great advantage in both time and memory consumptions, suggesting a tremendous potential of applying lower scaling doubly hybrid density functionals to complex large systems.

Key words: Density functional theory, Doubly hybrid density functional, Density fitting, Low scaling algorithm

CLC Number: 

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