[QE-users] help with turbo-davidson not converging

[Timrov Iurii]

Dear Gabriele,


> well, I reasoned that the VdW correction  might better account for
> possible long range inter ligand non-bonding interactions (ie between the P
> containing cages and the flat 2 rings ligand (bipyridine))


Ok, maybe that's correct, I am not an expert in that. But I would try without the VdW correction and see if it is possible to converge the calculation.


Concerning pseudopotentials, I suggest to use those recommended in the SSSP library:

https://www.materialscloud.org/discover/sssp/table/efficiency


You use 25/250 Ry for the cutoff, which is probably too low. If you use SSSP then use the cutoffs recommended there.


Also, I would try to perform a calculation with the Martyna-Tuckerman correction (if I am not wrong you can use this correction if the supercell is twice as large as the molecule).


Greetings,

Iurii


--
Dr. Iurii Timrov
Postdoctoral Researcher
STI - IMX - THEOS and NCCR - MARVEL
Swiss Federal Institute of Technology Lausanne (EPFL)
CH-1015 Lausanne, Switzerland
+41 21 69 34 881
http://people.epfl.ch/265334
________________________________
From: balducci at units.it <balducci at units.it>
Sent: Friday, June 26, 2020 5:55:19 PM
To: Timrov Iurii
Cc: users at lists.quantum-espresso.org
Subject: Re: [QE-users] help with turbo-davidson not converging

hi

thank you very much for the quick reply

> That's the main problem! You should start exactly from this point. You need=
>  to understand every step you do, otherwise what is the point?
>
>
> I would recommend to go through the tutorial about TDDFPT:
>
> http://indico.ictp.it/event/7921/session/325/contribution/1280/material/0/0=
> .pdf
>
>
> What is your input for PW calculation? In the links that you provided there=
>  is no one pointing to the PW input. But from the PW output it seems that y=

sorry about that: by mistake I copied twice the same file. Now the
correct scf input is in place:

http://www.dsch.univ.trieste.it/~balducci/tmp/turbo-davidson-problem/scf.in.txt

> ou are using the VdW correction - do you really need it? For an isolated mo=
> lecule there is no need in the VdW correction. So maybe it would be useful =

well, I reasoned that the VdW correction  might better account for
possible long range inter ligand non-bonding interactions (ie between the P
containing cages and the flat 2 rings ligand (bipyridine))

thanks again
cheers
-g

--
Gabriele Balducci - Dipartimento di Scienze Chimiche e Farmaceutiche - Via
L. Giorgieri 1 I-34127 TRIESTE tel: I-040-5583957 fax: I-040-5583903 e-mail:
balducci at units.it Please, if possible, don't send me MS Word or PowerPoint
attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html
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