Hi Mayuri,
Please try to more extra bands by using nbnd, it usually helps convergence.
Jibiao Li
--Original--
From:
"Quantum ESPRESSO users
On Mon, Mar 29, 2021 at 6:54 PM Jessica Johnson
wrote:
I understood that anharmonicity is taken into account with the inclusion of
> second and third order energy derivatives.
>
anharmonicity "may" be taken into account with the inclusion of second and
third order energy derivatives, but in
Dear QE users,
I am experiencing an issue while incorporating SOC in the system. I have
tried with relax, using different pseudopotentials (PAW, USPP, ONCV),
varying convergence threshold, increasing electron maxstep, varying
K-points etc in the input file. But still the convergence is not
Dear Quantum Espresso experts, I am having trouble calculating the phonon bands of graphene. First, I took the cif-file of the already relaxed graphite cell from the Materials Project site https://next-gen.materialsproject.org/ and made graphene cell from it by hand.Then I relaxed the cell
The coordinates of the high-symmetry points in matdyn.in should be in cartesian
not crystal because you are specifying q_in_band_form=.true.
Cheers,
Vahid
Vahid Askarpour
Department of physics and atmospheric science
Dalhousie University
Halifax, NS
CANADA
On Mar 30, 2021, at 11:19 AM, Evgenii
On Tue, Mar 30, 2021 at 4:20 PM Evgenii wrote:
> Dielectric Tensor:
>
> 166.332153320312 0.
> 166.332275390625 0.
> 0. 0. 1.116060253916
Dear Evgeniy,
I use the following for my graphene dispersion. Please note that the actual
coordinates depend on the PSP.
4
0.0 0.0 0.0 150 ! G
0.000 -0.577588 0.0 150 ! M
-0.3334706 -0.577588 0.0 150 ! K
0.0 0.0 0.0 1
So the matdyn.x code will automatically set 150 points between the
You have specified the q-points in crystal fractionary units, hence you have to
specify q_in_cryst_coord=.true.
This can be safely used in conjunction with q_in_band_form, which is a
completely unrelated option.
Also:
You way of specifying the cell parameters is discouraged and may cause
Hello you can take into account anharmonicity with the d3q code which is
included in QE, but also has its own homepage at https://anharmonic.github.io/
where you may find more documentation and examples. In particular, I recently
added an example on how to compute the vibrational spectral
Dear Vahid, If we use the default values of the q_in_band_form variables, then how do we find intermediate points between the points of high symmetry, as for example on this site https://www.afs.enea.it/buonocor/graphane-with-phonon.html ? Are intermediate points always needed, we noticed that in
Hi, Jessica
> 2021/03/30 1:53、Jessica Johnson のメール:
>
> I have a very general question about Raman calculations (I will include that
> I am using QE version 6.4.1 per the posting guidelines in case that helps my
> answer my question).
The derivatives of the potential give the T^2 and T^3
> Using a k-points grid that includes the K point can be a source of troubles,
> I would recommend using 16x16x1 or even 32x32x1 for better results.
p.s. and treat it as a metal, adding some smearing, to avoid the absurd
dielectric constant
--
Lorenzo Paulatto - Paris
On Mar 30 2021, at 5:00
> 2021/03/31 1:00、Lorenzo Paulatto のメール:
>
> Hello you can take into account anharmonicity with the d3q code which is
> included in QE,
This may be the most sophisticated way to account for the
anharmonicity from first principle. I'm impress by the ingeniousness.
Thank you for your notice.
While we are talking about interesting ways to include anharmonic
effects, it's worth taking a look at SSCHA: http://sscha.eu/
Not necessarily computationally inexpensive.
On Wed, 2021-03-31 at 07:20 +0900, Kazume NISHIDATE wrote:
> > 2021/03/31 1:00、Lorenzo Paulatto のメール:
> >
> > Hello you
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