[DFTB-Plus-User] How to use Waveplot in time-dependent calculations like Verlet or ElectronDynamics

[Bálint Aradi]

Dear Wanzhen,

> I’m doing time-dependent calculations using ElectronDynamics and I want
> to obtain the DFT-density-like charge densities on girds at each timestep.
> 
> I’ve read the instructions about Waveplot that both DetailedXml and
> EigenvecBin files are required to output the .cube file. So my question
> is how to obtain time-dependent .xml and eigenvec.bin files so that
> time-dependent  .cube files could be generated.

That is unfortunately currently not possible. At its current
implementation, Waveplot uses the eigenvectors in order to create the
molecular orbitals on the grid and to add them up to obtain the total
density. The electronic dynamics, on the other hand, produces only
density matrices.

A student of mine currently works on a reimplementation of Waveplot,
which (apart of being hopefully much more efficient than the current
one), should also be able to deal with density matrices. With a bit of
luck, it may get into the 21.1 release (around April/May next year)-

> Also, I guess this is a question for calculations like molecular
> dynamics, does anyone have any ideas?

For MD, there is a workaround. One just picks the geometries/snapshots
one wishes to visualize, then recalculates them in individual static
calculations and visualizes the densities via the eigenvectors with
Waveplot. Maybe not the most elegant approach, but quite viable. Also,
it prevents the generation of lot of unnecessary data (as compared to
outputting the eigenvectors really at every MD-step...)

Best regards,

Bálint

-- 
Dr. Bálint Aradi
Bremen Center for Computational Materials Science, University of Bremen
http://www.bccms.uni-bremen.de/cms/people/b-aradi/


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: OpenPGP digital signature
URL: <http://mailman.zfn.uni-bremen.de/pipermail/dftb-plus-user/attachments/20201203/c5f4ef03/attachment.sig>