Implementation and application of a DFT + U + V approach within the all-electron FLAPW method

Physical review. B./Physical review. B, vol. 114

Abstract

We present an implementation of the density-functional theory DFT + U + V formalism within the all-electron full-potential linearized augmented–plane-wave (FLAPW) method as implemented in the FLEUR code. The DFT + U + V formalism extends DFT, supplemented by the on-site Coulomb interaction U , to address local correlation effects in localized states by incorporating intersite Coulomb interaction terms V . It holds promise for improving charge and bond disproportionation, charge and orbital ordering, charge-density-wave formation, charge transfer, and the intersite correlation resulting from hybridization between states of neighboring sites in a solid. U and V parameters are obtained from first principles using the constrained random-phase approximation (cRPA) by employing two different atom basis representations to project the screened Coulomb interaction: the Wannier and the muffin–tin basis functions. We investigate in detail the impact of the V term for typical covalently bonded materials like graphene, for bulk semiconductors such as silicon and germanium, and for charge-transfer insulators like NiO. Our results demonstrate an improvement in accuracy of specific properties across these systems, providing a framework for describing materials with different interaction regimes. We compare our DFT + U + V results using our cRPA parameter sets with (i) previous DFT + U + V calculations employing pseudopotential approximations, (ii) experimental results, and (iii) our G W results.

Authors 6

1. W. Beida Aachen

   RWTH Aachen University · Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich

   RWTH Aachen University

2. Gustav Bihlmayer

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich

3. Christoph Friedrich

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich

4. Gregor Michalicek

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich

5. Daniel Wortmann

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich

6. Stefan Blügel Aachen

   RWTH Aachen University · Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich

   RWTH Aachen University