A Filon-like integration strategy for calculating exact exchange in periodic boundary conditions: a plane-wave DFT implementation

Materials Theory

article

Bylaska, Eric J¹  Waters, Kevin²  Hermes, Eric D³  Zádor, Judit³  Rosso, Kevin M⁴ 

[1] Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory;Department of Physics, Michigan Technological University;Combustion Research Facility, Sandia National Laboratories;Fundamental Sciences Division, Pacific Northwest National Laboratory

关键词: NWChem;    High-performance chemistry;    Plane-wave DFT;    Pseudopotentials;    Projector augmented wave;    PAW;    PSPW;    Ab initio Molecular Dynamics;    AIMD;    Periodic exact exchange;    UHF;    DFT;    Electron transfer;   

DOI  :  10.1186/s41313-020-00019-9

学科分类：社会科学、人文和艺术（综合）

来源: Springer

【 摘 要 】

An efficient and accurate approach for calculating exact exchange and other two-electron integrals has been developed for periodic electronic structure methods. Traditional approaches used for integrating over the Brillouin zone in band structure calculations, e.g. trapezoidal or Monkhorst-Pack, are not accurate enough for two-electron integrals. This is because their integrands contain multiple singularities over the double integration of the Brillouin zone, which with simple integration methods lead to very inaccurate results. A common approach to this problem has been to replace the Coulomb interaction with a screened Coulomb interaction that removes singularities from the integrands in the two-electron integrals, albeit at the inelegance of having to introduce a screening factor which must precomputed or guessed. Instead of introducing screened Coulomb interactions in an ad hoc way, the method developed in this work derives an effective screened potential using a Filon-like integration approach that is based only on the lattice parameters. This approach overcomes the limitations of traditionally defined screened Coulomb interactions for calculating two-electron integrals, and makes chemistry many-body calculations tractable in periodic boundary conditions. This method has been applied to several systems for which conventional DFT methods do not work well, including the reaction pathways for the addition of H2 to phenol and Au$_{20}^{-}$ nanoparticle, and the electron transfer of a charge trapped state in the Fe(II) containing mica, annite.

【 授权许可】

CC BY