processing XAS spectra

[Carles]

Dear all,

I am trying to compute the XAS spectrum at the K-edge on Zn (about 9.7 keV) with RT-TDDFT. 

I use, in atomic units:

----------------------------------------------------------

rt_tddft

print dipole field energy convergence

tmax 200.0

dt 0.005

  tag "kick_x"

  field "kick"

 type delta

 polarization x

 max 0.0001

end

 excite "system" with "kick"

 end

task dft rt_tddft

------------------------------------------------------------------

I would expect the spectrum decays for energies smaller than the K-edge, but it does not decay... it seems it keeps oscillating showing more picks. Do you know why? Can it be a problem of post-processing of the dipole signal? or maybe the kick is too small in amplitude (but in that case it should give LR-TDDFT, so that "sticks", isn't it?), or the dt is too large for the time sampling? or maybe the total propagation too short?

Thank you!

Carles

[Niri Govind]

Hi Carles,

Can you post or email me the complete input file ?  

The dt and kick you are using appear ok. It could either be the total propagation is too short or the damping in the post-processing. 

Best,

-Niri

Niri Govind

PNNL

niri....@pnnl.gov

--
You received this message because you are subscribed to the Google Groups "NWChem Forum" group.
To unsubscribe from this group and stop receiving emails from it, send an email to nwchem-forum...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/nwchem-forum/bfe703cc-7345-4dbe-b74a-ad70eeb2bdb0n%40googlegroups.com.

[Carles]

Hi Niri,

many thanks, I have errors when trying to post the file...

I send it to you.

Thank you,

Carles

El dia dijous, 25 de febrer de 2021 a les 16:41:03 UTC+1, niri....@gmail.com va escriure:

[Edoardo Aprà]

try renaming the file with a .txt suffix or upload  them to a publicly accessible website (e.g. google drive)

[Carles]

Hi Edoardo,

thanks a lot, I am posting it as .txt. 

I am trying to get a coorrect XAS for the molecule Zn(BzO)2(SC(NH2)2)2.

Best wishes,

Carles

El dia dijous, 25 de febrer de 2021 a les 18:17:37 UTC+1, Edoardo Aprà va escriure: