Re: [QE-users] Band structure calculation
Hi,
it is always a good practice to look at the documentation first.
Here, you can find some answers to your questions:
https://www.quantum-espresso.org/Doc/INPUT_PW.html#idm1487
nks: Number of supplied special k-points.
So, you decide how many points you want in your path (e.g., 50) and fix nks
to that value.
How to write the k-point path: given that your crystal is 1D, this is
an easy task. As you might read from the above link,
you specify the units of supplied k-points after K_POINTS. Let's use
'crystal' units and let us suppose that the direction of periodicity
of your crystal is the x one.
Your path (in crystal units) begins from -0.5 0.0 0.0 and ends to 0.5 0.0
0.0. As an example you can specify
K_POINTS { crystal }
11
-0.5 0.0 0.0. 1.0
-0.4 0.0 0.0. 1.0
-0.3 0.0 0.0. 1.0
-0.2 0.0 0.0. 1.0
-0.1 0.0 0.0. 1.0
0.0 0.0 0.0. 1.0
0.1 0.0 0.0. 1.0
0.2 0.0 0.0. 1.0
0.3 0.0 0.0. 1.0
0.4 0.0 0.0. 1.0
0.5 0.0 0.0. 1.0
A smooth band structure plot would require a finer division of the [-0.5
0.0 0.0] - [0.5 0.0 0.0] segment.
The fourth column (that with all the "1.0") contains k-points weights that
would be suitably set in the self-consistent calculation, but they do not
affect the results in a band structure not self consistent calculation (and
can be set to any value).
Giovanni
--
Giovanni Cantele, PhD
CNR-SPIN
c/o Dipartimento di Fisica
Universita' di Napoli "Federico II"
Complesso Universitario M. S. Angelo - Ed. 6
Via Cintia, I-80126, Napoli, Italy
e-mail: giovanni.cant...@spin.cnr.it
Phone: +39 081 676910
Skype contact: giocan74
ResearcherID: http://www.researcherid.com/rid/A-1951-2009
Web page: https://sites.google.com/view/giovanni-cantele/home
Il giorno dom 25 dic 2022 alle ore 17:23 Rameswar Bhattacharjee <
rb1...@georgetown.edu> ha scritto:
> Hi Everyone,
> I am trying to do a band structure calculation of a 1D organic crystal.
> The path of the band should be * -pi/a-gamma-pi/a* as used in the
> previous literature. Can anyone tell me how to write the k-path from -pi/a
> to +pi/a via gamma point in the QE input? Also, how to choose the "nks"
> value for each k-points coordinate.
>
> Any suggestion would be highly appreciated. I am attaching an image from a
> previous literature for a sample reference. Thank you in advance and Merry
> Christmas to all
>
> Rameswar Bhattacharjee
> Georgetown University
> ___
> The Quantum ESPRESSO community stands by the Ukrainian
> people and expresses its concerns about the devastating
> effects that the Russian military offensive has on their
> country and on the free and peaceful scientific, cultural,
> and economic cooperation amongst peoples
> ___
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> users mailing list users@lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users
___
The Quantum ESPRESSO community stands by the Ukrainian
people and expresses its concerns about the devastating
effects that the Russian military offensive has on their
country and on the free and peaceful scientific, cultural,
and economic cooperation amongst peoples
___
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list users@lists.quantum-espresso.org
https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] How to specify starting magnetization for different intermediate images in a single NEB input
Dear Parveen Rawal It depends on the system, whose physics you only know. It seems possible that a triplet ground state evolves in a different singlet ground state through the minimum energy path represented by the two low-energy branches of the two paths (the triplet one on the left of the crossing point, the singlet one on the right of the crossing point). HTH Giuseppe Quoting PARVEEN N/A : Thank you very much Prof. Giuseppe Mattioli for your answer. I have tried to calculate pathways using both spin states. Indeed, there is a crossing between the two spin surfaces (attached picture). My follow up question is how I can determine the minimum energy crossing point out of these two surfaces using QE. On Fri, Dec 16, 2022 at 1:17 PM Giuseppe Mattioli < giuseppe.matti...@ism.cnr.it> wrote: Dear Parveen Rawal AFAIK, an effective and correct way to deal with the crossing of different spin surfaces in ground state calculations is to calculate the whole path twice, using both spin states, in order to evaluate where the crossing happens. I suppose you cannot constraint magnetization for a single image, using tot_magnetization you can only fix it along the path. HTH Giuseppe Quoting PARVEEN N/A : > Dear All, > I have a general question regarding NEB input. I want to study a system in > which there are two intermediate images with different magnetic sites. For > these sites, I wish to specify different starting magnetizations for > different NEB images. How can I mention different starting magnetizations > for different intermediate images in a single NEB input? > > Parveen Rawal, > Research Scholar > IIT Roorkee GIUSEPPE MATTIOLI CNR - ISTITUTO DI STRUTTURA DELLA MATERIA Via Salaria Km 29,300 - C.P. 10 I-00015 - Monterotondo Scalo (RM) Mob (*preferred*) +39 373 7305625 Tel + 39 06 90672342 - Fax +39 06 90672316 E-mail: ___ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users GIUSEPPE MATTIOLI CNR - ISTITUTO DI STRUTTURA DELLA MATERIA Via Salaria Km 29,300 - C.P. 10 I-00015 - Monterotondo Scalo (RM) Mob (*preferred*) +39 373 7305625 Tel + 39 06 90672342 - Fax +39 06 90672316 E-mail: ___ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] Band structure calculation
Thank you Giovanni for such a wonderful explanation. It helps a lot
especially when someone is not very familiar with this field. I will go
through the documentation for more information regarding band structure.
Rameswar
On Wed, Dec 28, 2022 at 5:12 AM Giovanni Cantele <
giovanni.cant...@spin.cnr.it> wrote:
> Hi,
> it is always a good practice to look at the documentation first.
>
> Here, you can find some answers to your questions:
> https://www.quantum-espresso.org/Doc/INPUT_PW.html#idm1487
>
> nks: Number of supplied special k-points.
> So, you decide how many points you want in your path (e.g., 50) and fix
> nks to that value.
>
> How to write the k-point path: given that your crystal is 1D, this is
> an easy task. As you might read from the above link,
> you specify the units of supplied k-points after K_POINTS. Let's use
> 'crystal' units and let us suppose that the direction of periodicity
> of your crystal is the x one.
> Your path (in crystal units) begins from -0.5 0.0 0.0 and ends to 0.5 0.0
> 0.0. As an example you can specify
> K_POINTS { crystal }
> 11
> -0.5 0.0 0.0. 1.0
> -0.4 0.0 0.0. 1.0
> -0.3 0.0 0.0. 1.0
> -0.2 0.0 0.0. 1.0
> -0.1 0.0 0.0. 1.0
> 0.0 0.0 0.0. 1.0
> 0.1 0.0 0.0. 1.0
> 0.2 0.0 0.0. 1.0
> 0.3 0.0 0.0. 1.0
> 0.4 0.0 0.0. 1.0
> 0.5 0.0 0.0. 1.0
>
> A smooth band structure plot would require a finer division of the [-0.5
> 0.0 0.0] - [0.5 0.0 0.0] segment.
> The fourth column (that with all the "1.0") contains k-points weights that
> would be suitably set in the self-consistent calculation, but they do not
> affect the results in a band structure not self consistent calculation (and
> can be set to any value).
>
> Giovanni
> --
>
> Giovanni Cantele, PhD
> CNR-SPIN
> c/o Dipartimento di Fisica
> Universita' di Napoli "Federico II"
> Complesso Universitario M. S. Angelo - Ed. 6
> Via Cintia, I-80126, Napoli, Italy
> e-mail: giovanni.cant...@spin.cnr.it
> Phone: +39 081 676910
> Skype contact: giocan74
>
> ResearcherID: http://www.researcherid.com/rid/A-1951-2009
> Web page: https://sites.google.com/view/giovanni-cantele/home
>
>
> Il giorno dom 25 dic 2022 alle ore 17:23 Rameswar Bhattacharjee <
> rb1...@georgetown.edu> ha scritto:
>
>> Hi Everyone,
>> I am trying to do a band structure calculation of a 1D organic crystal.
>> The path of the band should be * -pi/a-gamma-pi/a* as used in the
>> previous literature. Can anyone tell me how to write the k-path from -pi/a
>> to +pi/a via gamma point in the QE input? Also, how to choose the "nks"
>> value for each k-points coordinate.
>>
>> Any suggestion would be highly appreciated. I am attaching an image from
>> a previous literature for a sample reference. Thank you in advance and
>> Merry Christmas to all
>>
>> Rameswar Bhattacharjee
>> Georgetown University
>> ___
>> The Quantum ESPRESSO community stands by the Ukrainian
>> people and expresses its concerns about the devastating
>> effects that the Russian military offensive has on their
>> country and on the free and peaceful scientific, cultural,
>> and economic cooperation amongst peoples
>> ___
>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
>> users mailing list users@lists.quantum-espresso.org
>> https://lists.quantum-espresso.org/mailman/listinfo/users
>
> ___
> The Quantum ESPRESSO community stands by the Ukrainian
> people and expresses its concerns about the devastating
> effects that the Russian military offensive has on their
> country and on the free and peaceful scientific, cultural,
> and economic cooperation amongst peoples
> ___
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> users mailing list users@lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users
___
The Quantum ESPRESSO community stands by the Ukrainian
people and expresses its concerns about the devastating
effects that the Russian military offensive has on their
country and on the free and peaceful scientific, cultural,
and economic cooperation amongst peoples
___
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list users@lists.quantum-espresso.org
https://lists.quantum-espresso.org/mailman/listinfo/users
