A Semiempirical Long-Range Corrected Exchange Correlation Functional Including a Short-Range Gaussian Attenuation (LCgau-B97)

作者：Song Jong Won^*; Peng Daoling; Hirao Kimihiko

来源：Journal of Computational Chemistry, 2011, 32(15): 3269-3275.

DOI：10.1002/jcc.21912

• density functional theory
• long-range correction
• range separation
• Gaussian short-range Hartree-Fock exchange
• semiempirical density functional theory
• charge transfer excitation
• Becke97

We applied an improved long-range correction scheme including a short-range Gaussian attenuation (LCgau) to the Becke97 (B97) exchange correlation functional. In the optimization of LCgau-B97 functional, the linear parameters are determined by least squares fitting. Optimizing mu parameter (0.2) that controls long-range portion of Hartree-Fock (HF) exchange to excitation energies of large molecules (Chai and Head-Gordon, J Chem Phys 2008, 128, 084106) and additional short-range Gaussian parameters (a = 0.15 and k = 0.9) that controls HF exchange inclusion ranging from short-range to mid-range (0.5-3 angstrom) to ground state properties achieved high performances of LCgau-B97 simultaneously on both ground state and excited state properties, which is better than other tested semiempirical density functional theory (DFT) functionals, such as omega B97, omega B97X, BMK, and M0x-family. We also found that while a small mu value (similar to 0.2) in LC-DFT is appropriate to the local excitation and intramolecular charge-transfer excitation energies, a larger mu value (0.42) is desirable in the Rydberg excitation-energy calculations.

• 出版日期2011-11-30