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

Tue Oct 13 08:25:12 CEST 2020

Dear Iurii,

Based on your recommendations, everything went well for q point #3.
However, q point #4 did not converge. Required converging iterations from q
point #1 to 3 is as following: 45 iterations for q1, 63 iterations for q2,
and 51 iterations for q3. q4 did not converge after 196 iterations. It took
6 days. Finally I stopped hp.x because of fluctuation in "residue" for
"chi".

Is it possible and reasonable to run hp.x for q point #1, 2, and 3
separately and use sum_pertq=.true. as well as start_q=1, last_q=3, and
perturb_only_atom(1)=.true. to calculate the U parameter? (There are
totally 4 q points)

alpha_mix is also reduced down to 0.01 as another alternative. It is still
running...

Any help will be greatly appreciated

Best,

Mohammad
ShirazU

On Fri, Sep 18, 2020 at 6:24 PM Timrov Iurii <iurii.timrov at epfl.ch> wrote:

> 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> 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> on behalf of
>> Mohammad Moaddeli <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>
>> 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> on behalf of
>>> Mohammad Moaddeli <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>
>>> 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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>>>
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>>
>> _______________________________________________
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>
> _______________________________________________
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso)
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