Publication details for Prof. David J. TozerGledhill, Jonathan D. & Tozer, David J. (2015). System-dependent exchange-correlation functional with exact asymptotic potential and HOMO approx -I. The Journal of Chemical Physics 143(2): 024104.
- Publication type: Journal Article
- ISSN/ISBN: 0021-9606 (print), 1089-7690 (electronic)
- DOI: 10.1063/1.4926397
- Further publication details on publisher web site
- Durham Research Online (DRO) - may include full text
Author(s) from Durham
Density scaling considerations are used to derive an exchange–correlation explicit density functional that is appropriate for the electron deficient side of the integer and which recovers the exact r → ∞ asymptotic behaviour of the exchange–correlation potential. The functional has an unconventional mathematical form with parameters that are system-dependent; the parameters for an N-electron system are determined in advance from generalised gradient approximation (GGA) calculations on the N- and (N − 1)-electron systems. Compared to GGA results, the functional yields similar exchange–correlation energies, but HOMO energies that are an order of magnitude closer to the negative of the vertical ionisation potential; for anions, the HOMO energies are negative, as required. Rydberg excitation energies are also notably improved and the exchange–correlation potential is visibly lowered towards the near-exact potential. Further development is required to improve valence excitations, static isotropic polarisabilities, and the shape of the potential in non-asymptotic regions. The functional is fundamentally different to conventional approximations.