LSPECTRALGW: Difference between revisions
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== Related | == Related tags and articles == | ||
{{TAG|LSPECTRAL}} | {{TAG|LSPECTRAL}} | ||
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[[Category:INCAR]][[Category:Many-Body Perturbation Theory]] [[Category:GW]] | [[Category:INCAR tag]][[Category:Many-Body Perturbation Theory]] [[Category:GW]] | ||
Revision as of 14:42, 8 April 2022
LSPECTRALGW = .FALSE. | .TRUE.
Default: LSPECTRALGW = .FALSE.
Description: LSPECTRALGW specifies to use the spectral method for calculating the self-energy.
If LSPECTRALGW = .TRUE. is set, the imaginary part of the self-energy is calculated from the imaginary part of screened potential by shifting the poles of by , where are the poles of the Green's function . Generally, LSPECTRALGW affects the compute time very little. QP energies also hardly change when LSPECTRALGW is modified. However, LSPECTRALGW = .TRUE. is usually slightly more robust, and should be selected for molecules and other systems with flat dispersion-less bands. One the other hand, LSPECTRALGW = .TRUE. seems to converge slightly slower, as the complex shift CSHIFT is decreased. Set this flag, if the QP energies show erratic behavior, for instance, if QP energies or Z-factors are not in the expected range of values (0.5<Z<0.9).