Jump to content

Requests for technical support from the VASP team should be posted in the VASP Forum.

ELPH WF CACHE PREFILL: Difference between revisions

From VASP Wiki
Remove wf cache is full error note
Csheldon (talk | contribs)
No edit summary
 
(One intermediate revision by one other user not shown)
Line 1: Line 1:
{{DISPLAYTITLE|ELPH_WF_CACHE_PREFILL}}
{{DISPLAYTITLE:ELPH_WF_CACHE_PREFILL}}
{{TAGDEF|ELPH_WF_CACHE_PREFILL|logical|.TRUE.}}
{{TAGDEF|ELPH_WF_CACHE_PREFILL|logical|.TRUE.}}


Description: Pre-fills the wavefunction cache before the main electron-phonon loop begins.
Description: Pre-fills the wavefunction cache before the main electron-phonon loop begins.
{{Available|6.5.0}}
{{Available|6.5.0}}
----
----
Line 15: Line 14:
* {{TAG|ELPH_WF_REDISTRIBUTE}}
* {{TAG|ELPH_WF_REDISTRIBUTE}}
* {{TAG|ELPH_WF_COMM_OPT}}
* {{TAG|ELPH_WF_COMM_OPT}}
* {{TAG|ELPH_MELS}}
[[Category:INCAR tag]][[Category:Electron-phonon_interactions]]
[[Category:INCAR tag]][[Category:Electron-phonon_interactions]]

Latest revision as of 13:35, 18 June 2026

ELPH_WF_CACHE_PREFILL = logical
Default: ELPH_WF_CACHE_PREFILL = .TRUE. 

Description: Pre-fills the wavefunction cache before the main electron-phonon loop begins.


When computing electron-phonon matrix elements, VASP caches wavefunctions fetched from remote MPI ranks (see ELPH_WF_CACHE_MB). With ELPH_WF_CACHE_PREFILL = .TRUE. (the default), all required wavefunctions are gathered into the cache in a single communication phase before the main loop starts. This means the loop itself runs with little or no inter-rank MPI traffic.

Setting ELPH_WF_CACHE_PREFILL = .FALSE. disables pre-filling; wavefunctions are then fetched on demand during the loop. This reduces the upfront communication cost but increases total MPI traffic and is generally slower.

Related tags and articles