LADDER: Difference between revisions
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Description: Controls whether the ladder diagrams are included in the {{TAG|BSE}} calculation. | Description: Controls whether the ladder diagrams are included in the {{TAG|BSE}} calculation. | ||
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{{TAG|LADDER}} is used together with {{TAG|LHARTREE}}. If {{TAG|LADDER}}=''.FALSE.'', the ladder diagrams (i.e. the exchange terms related to <math>W</math> or the screened exchange) are not included. | {{TAG|LADDER}} is used together with {{TAG|LHARTREE}}. If {{TAG|LADDER}}=''.FALSE.'', the ladder diagrams (i.e. the exchange terms related to <math>W</math> or the screened exchange) are not included. | ||
If {{TAG|HARTREE}}=''.FALSE.'', the Hartree diagrams or bubble diagrams are not included. The following table summarizes all possible combinations: | If {{TAG|HARTREE}}=''.FALSE.'', the Hartree diagrams or bubble diagrams are not included. The following table summarizes all possible combinations: | ||
::{| cellpadding="5" cellspacing="0" border="1" | ::{| cellpadding="5" cellspacing="0" border="1" | ||
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| .FALSE. || .FALSE. || independent particle picture | | .FALSE. || .FALSE. || independent particle picture | ||
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Revision as of 12:06, 16 January 2017
LADDER = [logical]
Default: LADDER = .TRUE.
Description: Controls whether the ladder diagrams are included in the BSE calculation.
LADDER is used together with LHARTREE. If LADDER=.FALSE., the ladder diagrams (i.e. the exchange terms related to or the screened exchange) are not included. If HARTREE=.FALSE., the Hartree diagrams or bubble diagrams are not included. The following table summarizes all possible combinations:
The last combination can be useful for sanity checks: the results must be identical to the results obtained using
[[{{{1}}}]] in the preceding calculations. If this is not the case, it usually implies that the one-electron
energies have been updated in the WAVECAR file, or that the WAVEDER file is not properly set up. The end of BSE explains how to recalculate
the WAVEDER file from an existing WAVECAR file.