[QE-users] Calculating U parameter for Ni in LiNiO2 using hp.x

Fri Sep 18 15:53:35 CEST 2020

Dear Mohammad,

Your system seems to be delicate to converge. So I found that the mixing parameter alpha_mix needs to be reduce further, down to 0.05 (which is very small). With this, you can converge the HP calculation for the third q point with the accuracy conv_thr_chi = 1.0d-5 (which is still fine).

By the way, if you want to test the convergence of the HP code for a specific q point, you can use the input parameters start_q and last_q and specify for which perturbed atom you do this. In your case, you need to specify the following in the input for HP:

   perturb_only_atom(1) = .true.
   start_q = 3
   last_q  = 3
Here is the documentation: https://www.quantum-espresso.org/Doc/INPUT_HP.html
Also, when using iverbosity = 4 the HP code prints a lot of information in the output. This is not really needed in this case. I would use iverbosity = 2.

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: users <users-bounces at lists.quantum-espresso.org> on behalf of Mohammad Moaddeli <mohammad.moaddeli at gmail.com>
Sent: Friday, September 18, 2020 6:14:48 AM
To: Quantum ESPRESSO users Forum
Subject: Re: [QE-users] Calculating U parameter for Ni in LiNiO2 using hp.x

Dear Iurii,

Unfortunately the q pont #3 did not converge. All input and output files are available in this link:

https://drive.google.com/file/d/1zWoYq3kfBfH-6bw8s5llDm-BYFxM3ndQ/view?usp=sharing

Any help will be greatly appreciated.

Regards,

Mohammad

On Wed, Sep 16, 2020 at 1:00 PM Timrov Iurii <iurii.timrov at epfl.ch<mailto:iurii.timrov at epfl.ch>> wrote:

Dear Mohammad,

> By changing the threshold values you mentioned, nscf calculation finished (no "cholesky" error)...

Great!

> ...but there is divergence in computing "chi".

The HP calculation for q points #1 and #2 has converged, but the problem is for the q point #3. In the HP input, please setup

alpha_mix(1) = 0.1

and try again.

Also I suggest to use the default value nmix = 4, because I have never tried changing it to something else (you are using nmix=5) and so I do not know what to expect.

Also note that the parameter conv_thr_chi = 1.0d-8 is very tight, so can try even something like conv_thr_chi = 1.0d-6 which should also be fine (because your calculations take a lot of time with 16 cores that you use).

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: users <users-bounces at lists.quantum-espresso.org<mailto:users-bounces at lists.quantum-espresso.org>> on behalf of Mohammad Moaddeli <mohammad.moaddeli at gmail.com<mailto:mohammad.moaddeli at gmail.com>>
Sent: Wednesday, September 16, 2020 7:21:53 AM
To: Quantum ESPRESSO users Forum
Subject: Re: [QE-users] Calculating U parameter for Ni in LiNiO2 using hp.x

Dear Iurii,

By changing the threshold values you mentioned, nscf calculation finished (no "cholesky" error), but there is divergence in computing "chi". Please find the link below. All input and output files are attached.

https://drive.google.com/file/d/1TWDQ3X_jG7HsgaVvhUiu3oVWt28g3DNz/view?usp=sharing

Best,

Mohammad

ShirazU

On Sun, Sep 13, 2020 at 2:13 PM Timrov Iurii <iurii.timrov at epfl.ch<mailto:iurii.timrov at epfl.ch>> wrote:

Dear Mohammad,

1.In the SCF input for the supercell you have:

conv_thr = 1.0d-20

This is extremely low! Try some value in-between 1.0d-10 and 1.d-15.

2.In the HP input for the supercell you have:

ethr_nscf = 1.D-14

This is also extremely low! Try the default value of 1.0d-11.

If you still have a problem when using e.g. conv_thr=1.d-10 and ethr_nscf=1.d-11 then please put input and output files on Google Drive or Dropbox and send a link to us (do not forget to check the permissions of the shared folder).

HTH

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: users <users-bounces at lists.quantum-espresso.org<mailto:users-bounces at lists.quantum-espresso.org>> on behalf of Mohammad Moaddeli <mohammad.moaddeli at gmail.com<mailto:mohammad.moaddeli at gmail.com>>
Sent: Sunday, September 13, 2020 6:12:27 AM
To: Quantum ESPRESSO users Forum
Subject: Re: [QE-users] Calculating U parameter for Ni in LiNiO2 using hp.x

Dear Lorenzo,

Thank you for your prompt reply.
Using qe_6.6 (in which calculating force and stress is implemented) the 221 supercell relaxed with the U obtained from the output of hp.x for the primitive cell, but the same error appeared. What do you recommend?

Best,

Mohammad,

ShirazU

On Mon, Sep 7, 2020 at 12:07 PM Lorenzo Paulatto <paulatz at gmail.com<mailto:paulatz at gmail.com>> wrote:
 > I am trying to calculate the U parameter for Ni in LiNiO2. The hp.x
 > (qe_6.5) runs without any error for the primitive cell, however the
 > "problems computing cholesky" error occurs for running a 2×2×1 supercell

The most likely cause is that you did a mistake in the atomic position
or cell size.

kind regards

--
Lorenzo Paulatto - Paris
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