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.
Meanwhile, Hubbard-corrected DFT (DFT+U) is a well-established correction to DFT [2]. While this correction does not directly target quasiparticle energies, it tends to improve their description while also addressing the self-interaction error inherent to DFT [3].
In this project, the student will unite these two approaches, and test this strategy on systems for which DFT is known to fail. This will involve...
- theoretical work assessing how best to combine Hubbard and Koopmans functionals
- implementing and testing Hubbard functionals in the koopmans package
- performing and analysing calculations on materials of scientific interest
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.
Meanwhile, Hubbard-corrected DFT (DFT+U) is a well-established correction to DFT [2]. While this correction does not directly target quasiparticle energies, it tends to improve their description while also addressing the self-interaction error inherent to DFT [3].
In this project, the student will unite these two approaches, and test this strategy on systems for which DFT is known to fail. This will involve...
- theoretical work assessing how best to combine Hubbard and Koopmans functionals - implementing and testing Hubbard functionals in the koopmans package - performing and analysing calculations on materials of scientific interest
- proficiency in Python is essential, as the project involves implementing functionality in the koopmans package
- 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
- proficiency in Python is essential, as the project involves implementing functionality in the koopmans package - 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. V. Anisimov et al., "Density-functional theory and NiO photoemission spectra", Phys. Rev. B 48, 16929 (1993)
3. M. Cococcioni et al., "Linear response approach to the calculation of the effective interaction parameters in the LDA + U method", Phys. Rev. B 71, 035105 (2005)
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. V. Anisimov et al., "Density-functional theory and NiO photoemission spectra", Phys. Rev. B 48, 16929 (1993) 3. M. Cococcioni et al., "Linear response approach to the calculation of the effective interaction parameters in the LDA + U method", Phys. Rev. B 71, 035105 (2005)
For more information, please contact Edward Linscott at edward.linscott@psi.ch
For more information, please contact Edward Linscott at edward.linscott@psi.ch
