[QE-users] Calculation stuck in the first iteration using meta GGA scan in QE 6.7.

[Paolo Giannozzi]

Meta-GGA functionals may easily give numerical problems, especially where
there is a lot of empty space

Paolo

On Wed, Apr 28, 2021 at 7:07 AM Raj <rajmaddipati95 at gmail.com> wrote:

> Hello Elgammal,
>
> I have already ran calculations with SSSP PP with suggested cutoffs and
> they are running well. Now, I want to run with scan exchange-correlation
> function using SCAN PP provided in qE website.  For this case, the
> iteration stuck in the first iteration itself. I am calculating for
> isolated oxygen atom using gamma points.
>
>
>
> Thank you.
>
>
>
>
>
> *From: *Karim Elgammal <elgammal at kth.se>
> *Sent: *28 April 2021 03:22
> *To: *Quantum ESPRESSO users Forum <users at lists.quantum-espresso.org>
> *Subject: *Re: [QE-users] Calculation stuck in the first iteration using
> meta GGA scan in QE 6.7.
>
>
>
> hi
>
>
>
> is there a specific reason for enforcing this specific PP?
>
>
>
> check the SSSP PP; with their recommended cutoffs as a starting point then
> maybe you can restart the same calculation with your preffered PP
>
>
>
> how is the vacuum around your molecule?
>
>
>
>
>
> On Tue, 27 Apr 2021 at 23:50, Karim Elgammal <egkarim at gmail.com> wrote:
>
> hi
>
>
>
> is there a specific reason for enforcing this specific PP?
>
>
>
> check the SSSP PP; with their recommended cutoffs as a starting point then
> maybe you can restart the same calculation with your preffered PP
>
>
>
> how is the vacuum around your molecule?
>
>
>
> On Mon, 26 Apr 2021 at 06:44, Raj <rajmaddipati95 at gmail.com> wrote:
>
> Dear all,
>
> I am performing scf calculation of isolated oxygen atom using SCAN
> pseudo-potential with gamma points. The calculation stuck in the first
> iteration and doesn’t progress ahead. I have tried with different smearing
> but still it stuck at the same point. I have tried with occupations=’fixed’
> for which the total energy is fluctuating with random numbers and not
> converging. I have tried increasing ecutwfc and decreasing convergence
> threshold, but no change. Some lines of output file as shown below .
>
> Thanks in advance.
>
> Regards
>
> Raj
>
>
>
> *IMPORTANT: XC functional enforced from input
> :
> Exchange-correlation= MGGA_X_SCAN MGGA_C_SCAN
>                                                                                                                          (
> 0   0   0   0   0 263 267)*
>
> *.*
>
> *.*
>
> *.*
>
> *number of k points=     1  Fermi-Dirac smearing, width (Ry)=  0.0147*
>
> *                       cart. coord. in units 2pi/alat*
>
> *        k(    1) = (   0.0000000   0.0000000   0.0000000), wk =
> 2.0000000*
>
>
>
> *     Dense  grid:  1184463 G-vectors     FFT dimensions: ( 180, 180, 180)*
>
>
>
> *     Estimated max dynamical RAM per process >     779.14 MB*
>
>
>
> *     Estimated total dynamical RAM >       1.52 GB*
>
>
>
> *     Initial potential from superposition of free atoms*
>
>
>
> *     starting charge    6.00000, renormalised to    6.00000*
>
>
>
> *     negative rho (up,down):  5.796E-03 0.000E+00*
>
> *     Starting wfcs are    4 randomized atomic wfcs +    3 random wfcs*
>
>
>
> *     total cpu time spent up to now is        5.2 secs*
>
>
>
> *     Self-consistent Calculation*
>
>
>
> *     iteration #  1     ecut=    75.00 Ry     beta= 0.70*
>
>
>
>
>
> _______________________________________________
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> users mailing list users at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users
>
> --
>
> Thank you and Best Regards;
>
> Yours;
> *Karim Elgammal*
>
>
>
> --
>
> Thank you and Best Regards;
>
> Yours;
> *Karim Elgammal*
>
>
>
>
> _______________________________________________
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> users mailing list users at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users



-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 206, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20210428/5e54ba54/attachment.html>