Journal Article

M06-SX screened-exchange density functional for chemistry and solid-state physics

Lia, Yaqi, Truhlar, Donald G., Heb, Xiao, Verma, Pragya, Liu, Zhonghua, Wang, Ying, Zhang, Lujia

2020

Overview

Screened-exchange hybrid density functionals are especially recommended for solid-state systems because they combine the advantages of hybrid functionals with the correct physics and lower computational cost associated with the attenuation of Hartree–Fock exchange at long range. We present a screenedexchange hybrid functional, M06-SX, that combines the functional form of the local revM06-L functional with a percentage of short-range nonlocal Hartree–Fock exchange. The M06-SX functional gives good results not only for a large set of training data but also for several databases quite different from the training data. The mean unsigned error (MUE) of the M06-SX functional is 2.85 kcal/mol for 418 atomic and molecular energies (AME418) in Minnesota Database 2019, which is better than all five other screened-exchange hybrid functionals tested in this work. The M06-SX functional also gives especially good results for semiconductor band gaps, molecular dissociation energies, noncovalent interactions, barrier heights, and electronic excitation energies excluding long-range charge transfer excitations. For the LC18 lattice constants database, the M06-SX functional gives an MUE of only 0.034 Å. Therefore, the M06-SX functional is well suited for studying molecular chemistry as well as solid-state physics.

• Publisher: National Academy of Sciences,Proceedings of the National Academy of Sciences
• Subject: Attenuation / band gap / Charge transfer / Chemistry / Computer applications / condensed-matter theory / Density / Exchanging / Excitation / INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY / Kohn-Sham density functional theory / lattice constants / Lattice parameters / molecular energetics / Organic chemistry / Physical Sciences / Physics / Solid state physics / Training