LSPECTRALGW: Difference between revisions

From VASP Wiki
No edit summary
No edit summary
Line 1: Line 1:
{{TAGDEF|LSPECTRALGW|.FALSE. {{!}} .TRUE.}}
{{TAGDEF|LSPECTRALGW|.FALSE. {{!}} .TRUE.|.FALSE.}}
{{DEF|LSPECTRALGW|.FALSE.|}}


Description: {{TAG|LSPECTRALGW}} specifies to use the spectral method for calculating the self-energy.
Description: {{TAG|LSPECTRALGW}} specifies to use the spectral method for calculating the self-energy.

Revision as of 18:18, 13 March 2017

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 is slightly more robust, and should be selected for molecules and other systems with flat 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.


Related Tags and Sections

LSPECTRAL

Example Calculations using this Tag


Contents