Publication: Improved electronic excitation energies from shape-corrected semilocal KohnâSham potentials
All || By Area || By YearTitle | Improved electronic excitation energies from shape-corrected semilocal KohnâSham potentials | Authors/Editors* | A. P. Gaiduk, D. S. Firaha, and V. N. Staroverov |
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Where published* | Phys. Rev. Lett. |
How published* | Journal |
Year* | 2012 |
Volume | 108 |
Number | |
Pages | 253005 |
Publisher | |
Keywords | |
Link | http://link.aps.org/doi/10.1103/PhysRevLett.108.253005 |
Abstract |
We propose a general method for obtaining accurate valence and Rydberg excitation energies from standard density-functional approximations in adiabatic linear-response time-dependent density-functional theory. The method consists in modeling the sum of Hartree (Coulomb) and exchange-correlation potentials, vHXC(r), by the Hartree-exchange-correlation potential of the corresponding partially ionized system in which a fraction of electron charge (δ=0.15 to 0.30, depending on the functional) is removed from the highest occupied Kohn-Sham orbital level. The model potential is less repulsive and closer to exact in valence and near asymptotic regions, so it yields more accurate Kohn-Sham orbitals and orbital eigenvalues. By applying this scheme to conventional local, semilocal, and hybrid density-functional approximations, we improve their accuracy for Rydberg excitations by almost an order of magnitude without sacrificing the already good performance for valence transitions. |
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