Density functional theory (DFT) is a go-to method for computationally predicting the structural and spectroscopic properties of materials and molecules. However, DFT is only approximate, and standard formulations of DFT exhibit some notable shortcomings. Our group has been developing Koopmans functionals [1], an extension to DFT that is far better at predicting quasiparticle-related quantities such as ionization potentials and electron affinities of molecules and band structures of bulk materials.
It is possible to augment Koopmans functionals with a Perdew-Zunger correction to address one-electron self-interaction error, ensuring that the functional is exact for one-electron systems [2]. This has already been done with great success, with the so-called KIPZ functional being the best performing Koopmans functional on certain benchmarks [3]. However, the KIPZ represents just one of several possible ways to add a Perdew-Zunger correction to Koopmans functionals, and the optimal method for doing so remains to be seen.
In this project, you will investigate how best to unite these two approaches. This will involve...
- theoretical work developing on possible strategies for combining Koopmans and Perdew-Zunger corrections
- implementing candidate functionals in Quantum ESPRESSO and the koopmans package
- assessing the performance of candidate functionals on well-established benchmarks
Density functional theory (DFT) is a go-to method for computationally predicting the structural and spectroscopic properties of materials and molecules. However, DFT is only approximate, and standard formulations of DFT exhibit some notable shortcomings. Our group has been developing Koopmans functionals [1], an extension to DFT that is far better at predicting quasiparticle-related quantities such as ionization potentials and electron affinities of molecules and band structures of bulk materials.
It is possible to augment Koopmans functionals with a Perdew-Zunger correction to address one-electron self-interaction error, ensuring that the functional is exact for one-electron systems [2]. This has already been done with great success, with the so-called KIPZ functional being the best performing Koopmans functional on certain benchmarks [3]. However, the KIPZ represents just one of several possible ways to add a Perdew-Zunger correction to Koopmans functionals, and the optimal method for doing so remains to be seen.
In this project, you will investigate how best to unite these two approaches. This will involve...
- theoretical work developing on possible strategies for combining Koopmans and Perdew-Zunger corrections - implementing candidate functionals in Quantum ESPRESSO and the koopmans package - assessing the performance of candidate functionals on well-established benchmarks
- coding proficiency is essential, as the project involves implementing novel functionalities in packages written in Fortran and Python
- familiarity with Linux operating systems is helpful
- completion of master's-level courses in computational materials science and atomistic modeling (e.g. EPFL's MSE-423 and MSE-468 or equivalent) is recommended
- coding proficiency is essential, as the project involves implementing novel functionalities in packages written in Fortran and Python - familiarity with Linux operating systems is helpful - completion of master's-level courses in computational materials science and atomistic modeling (e.g. EPFL's MSE-423 and MSE-468 or equivalent) is recommended
1. E. Linscott et al., "koopmans: an open-source package for accurately and efficiently predicting spectral properties with Koopmans functionals", J. Chem. Theory Comput. (2023)
2. J. Perdew and A. Zunger, "Self-interaction correction to density-functional approximations for many-electron systems", Phys. Rev. B 23, 5048 (1981)
3. N. Colonna et al., "Koopmans-compliant functionals and potentials and their application to the GW100 test set", J. Chem. Theory Comput. 15, 3, 1905 (2019)
1. E. Linscott et al., "koopmans: an open-source package for accurately and efficiently predicting spectral properties with Koopmans functionals", J. Chem. Theory Comput. (2023) 2. J. Perdew and A. Zunger, "Self-interaction correction to density-functional approximations for many-electron systems", Phys. Rev. B 23, 5048 (1981) 3. N. Colonna et al., "Koopmans-compliant functionals and potentials and their application to the GW100 test set", J. Chem. Theory Comput. 15, 3, 1905 (2019)
For more information, please contact Edward Linscott at edward.linscott@psi.ch
For more information, please contact Edward Linscott at edward.linscott@psi.ch
