[QE-users] [EXT] Environ and 2D slab pp.x potential

Wed Jul 22 17:35:51 CEST 2020

I am sorry, I may not be familiar with the terminology. You want to run a simulation with constant applied potential? Do you plan to do a molecular dynamics simulation or just total energy/geometry relaxations? With Environ you can perform simulations with constant electrode charge, which can be converted into a constant potential simulations. These simulations could include a reasonable description of the solvent interface, as well as a reasonable description of the electrochemical diffuse layer. You could vary the charge in the substrate (i.e. tot_charge in the pw input file) so as to obtain the potential drop that you want, or if you are interested in computing interfacial energies as a function of different potentials, you could use an approach based on Legendre transforms such as the one described in N. Hörmann et al, J. Chem. Phys. 150, 041730 (2019).
Best,

Oliviero

On Jul 22, 2020, at 9:53 AM, Antonio Crepaldi <antonio.crepaldi.lanza at gmail.com<mailto:antonio.crepaldi.lanza at gmail.com>> wrote:

Dear Oliviero,

Thank you very much for your detailed explanation!
I would just like to ask you if it is possible to make a constant mu calculation with environ. I've read in the manual that this requires ESM, but I don't know if this is compatible with the environ setup.
Thank you again.
Best,

Antonio

Il giorno mar 21 lug 2020 alle ore 17:54 Andreussi, Oliviero <Oliviero.Andreussi at unt.edu<mailto:Oliviero.Andreussi at unt.edu>> ha scritto:
I am sorry my answer can be misleading. The wave function and the density also depend on the environment, but the point is that PP does not recompute them, it just reads them from the saved wfc files and plot them. PP instead needs to recompute the potentials to plot them and this is where the missing environ makes the results meaningless.

I hope this helps,

Best,

Oliviero

On Jul 21, 2020, at 10:47 AM, Andreussi, Oliviero <Oliviero.Andreussi at unt.edu<mailto:Oliviero.Andreussi at unt.edu>> wrote:

Dear Antonio,

Thanks for reporting this issue and for trying Environ for your simulations. I am afraid the documentation of Environ needs to be improved on the point that you report, as this is not the first time I see this question.

Environ is not coupled with the PP code. If PP is used to plot quantities that do not depend on the environment, such as the wavefunction, the density, etc., it should work fine. However, you cannot use PP to plot quantities that depend on the environment, namely the electrostatic potential. For this purpose, you can turn on the verbosity of Environ using the verbose keyword. If you set verbose = 2 (or higher) you should get some .cube files that you can use to visualize properties of the simulation cell, in particular the electrostatic potential. Cubefiles are read by many programs and can be processed relatively easily with scripts.

Don’t hesitate to let me know if you have any problem with running Environ. You may also consider joining the google group created to support Environ users, there are not too many discussions right now, but it would be nice to build a collection of known problems, solutions and suggestions. quantum-environ-users<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgroups.google.com%2Fforum%2F%3Fhl%3Den%23!forum%2Fquantum-environ-users&data=02%7C01%7Coliviero.andreussi%40unt.edu%7C883c9e7711f7412393b708d82e4f31a4%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637310264966371043&sdata=lPqnsBoTuLd%2FyGG3dFHx2gIRWosfJ9AsDh1VoCdGgxc%3D&reserved=0> (https://groups.google.com/forum/?hl=en#!forum/quantum-environ-users<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgroups.google.com%2Fforum%2F%3Fhl%3Den%23!forum%2Fquantum-environ-users&data=02%7C01%7Coliviero.andreussi%40unt.edu%7C883c9e7711f7412393b708d82e4f31a4%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637310264966381038&sdata=2D%2Bjkelhj5dpTHSEtSr6PDkrKTPIInPQMvsJG2EznKw%3D&reserved=0>)

Best,

Oliviero

Oliviero Andreussi
--
Assistant Professor
Department of Physics
University of North Texas
Email: oliviero.andreussi at unt.edu<mailto:oliviero.andreussi at unt.edu>
Phone: +1-(940)-369-5316
Skype: olivieroandreussi
Web: https://www.materialab.org<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.materialab.org%2F&data=02%7C01%7Coliviero.andreussi%40unt.edu%7C883c9e7711f7412393b708d82e4f31a4%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637310264966381038&sdata=tK05iKxaG0dKOHXN4IUxF8twFc0f1Bjy4hriZTv9Bkk%3D&reserved=0>

On Jul 21, 2020, at 8:42 AM, Antonio Crepaldi <antonio.crepaldi.lanza at gmail.com<mailto:antonio.crepaldi.lanza at gmail.com>> wrote:

Dear QE users and developers,

I'm currently trying to simulate a charged 2D slab embedded in water. I'm using two planar countercharges as explained in Example 5 of Environ. The computation does not have any convergence problem, however, when I plot the total electrostatic potential (plot_num=11 in pp.x) I do not get a flat potential in the vacuum region screened by the countercharges. I would expect to find a flat potential in that region and be able to use it as a reference for further calculations.
Here is my environ input

&ENVIRON
   verbose = 0
   environ_thr = 1.d0
   environ_type = 'input'
   env_electrostatic = .true.
   env_static_permittivity = 80
   env_surface_tension = 0.D0
   env_pressure = 0.D0
   env_external_charges = 2
/
&BOUNDARY
   solvent_mode = 'full'
/
&ELECTROSTATIC
   pbc_correction = 'parabolic'
   pbc_dim = 2
   pbc_axis = 3
   tol = 5.D-13
   !inner_tol = 5.D-18
/
EXTERNAL_CHARGES (bohr)
2. 0.0 0.0 -14.29 1.0 2 3
2. 0.0 0.0  14.29 1.0 2 3

 Thank you very much for your help.
Best,

Antonio Crepaldi-Lanza

--
Department of Physics "Aldo Moro"
University of Bari
_______________________________________________
Quantum ESPRESSO is supported by MaX (https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.max-centre.eu%2Fquantum-espresso&data=02%7C01%7Coliviero.andreussi%40unt.edu%7Cbf10c4b1071745838eb008d82d7c03d9%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637309357952927330&sdata=pvaXJ16pf8n%2Bmah6qe4wX7cgT9o7bvGnO4f6FrrYukM%3D&reserved=0<https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.max-centre.eu%2Fquantum-espresso&data=02%7C01%7Coliviero.andreussi%40unt.edu%7C883c9e7711f7412393b708d82e4f31a4%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637310264966391035&sdata=38TOc%2F%2B4xmKTHySJFL6wZY0Wx8ABT7KimJzm2WrR0uk%3D&reserved=0>)
users mailing list users at lists.quantum-espresso.org<mailto:users at lists.quantum-espresso.org>
https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.quantum-espresso.org%2Fmailman%2Flistinfo%2Fusers&data=02%7C01%7Coliviero.andreussi%40unt.edu%7Cbf10c4b1071745838eb008d82d7c03d9%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637309357952937325&sdata=j2PM%2FJTHGhBVzsNqYw5ZmvWAj3XuuafBVypy2DG5am4%3D&reserved=0<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.quantum-espresso.org%2Fmailman%2Flistinfo%2Fusers&data=02%7C01%7Coliviero.andreussi%40unt.edu%7C883c9e7711f7412393b708d82e4f31a4%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637310264966401027&sdata=%2BjuDjqfCUjrWeNawFWCl0wBj%2FfkH80kHuoiwVc%2BiDCI%3D&reserved=0>

_______________________________________________
Quantum ESPRESSO is supported by MaX (https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.max-centre.eu%2Fquantum-espresso&data=02%7C01%7Coliviero.andreussi%40unt.edu%7C3c06ec5dcb694d44a47808d82d8d85ee%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637309433158048698&sdata=oxwo%2B%2F%2BVi7N5kgQ7evuEJYeZMkZwz8s8wZIrm4Q%2Fcg0%3D&reserved=0<https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.max-centre.eu%2Fquantum-espresso&data=02%7C01%7Coliviero.andreussi%40unt.edu%7C883c9e7711f7412393b708d82e4f31a4%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637310264966401027&sdata=Rhy3j%2FoToWrjRIt7xt0Ja5f5%2FH9fUicdVqM404nd5kw%3D&reserved=0>)
users mailing list users at lists.quantum-espresso.org<mailto:users at lists.quantum-espresso.org>
https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.quantum-espresso.org%2Fmailman%2Flistinfo%2Fusers&data=02%7C01%7Coliviero.andreussi%40unt.edu%7C3c06ec5dcb694d44a47808d82d8d85ee%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637309433158048698&sdata=X30Qq0KT%2BDtSZHCZrVo5%2BhCFPqGdBnGJ%2FFfE7%2FFQBDI%3D&reserved=0<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.quantum-espresso.org%2Fmailman%2Flistinfo%2Fusers&data=02%7C01%7Coliviero.andreussi%40unt.edu%7C883c9e7711f7412393b708d82e4f31a4%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637310264966411028&sdata=BzQcluqBdgXXs2eUv0wYecEZYvalAcpZuehXN35Iff0%3D&reserved=0>

_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso<https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.max-centre.eu%2Fquantum-espresso&data=02%7C01%7Coliviero.andreussi%40unt.edu%7C883c9e7711f7412393b708d82e4f31a4%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637310264966421023&sdata=%2Fz6Ixmb7IoAl3UOx4LJUDCo62SJ6UgvOLMV2Y%2Bg15vs%3D&reserved=0>)
users mailing list users at lists.quantum-espresso.org<mailto:users at lists.quantum-espresso.org>
https://lists.quantum-espresso.org/mailman/listinfo/users<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.quantum-espresso.org%2Fmailman%2Flistinfo%2Fusers&data=02%7C01%7Coliviero.andreussi%40unt.edu%7C883c9e7711f7412393b708d82e4f31a4%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637310264966421023&sdata=TtqbnKvUN6OnmJiTbZDscdstkhYEjHW%2BL%2B1iNEEUY5M%3D&reserved=0>
_______________________________________________
Quantum ESPRESSO is supported by MaX (https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.max-centre.eu%2Fquantum-espresso&data=02%7C01%7Coliviero.andreussi%40unt.edu%7C883c9e7711f7412393b708d82e4f31a4%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637310264966461010&sdata=Cb6uC1pSzkL4ZO1bWOXWZd5A%2FjSjvD7mpoKCI53XecI%3D&reserved=0)
users mailing list users at lists.quantum-espresso.org<mailto:users at lists.quantum-espresso.org>
https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.quantum-espresso.org%2Fmailman%2Flistinfo%2Fusers&data=02%7C01%7Coliviero.andreussi%40unt.edu%7C883c9e7711f7412393b708d82e4f31a4%7C70de199207c6480fa318a1afcba03983%7C0%7C0%7C637310264966461010&sdata=cilJg%2FMI8GIFB50fz%2BoUfKc0TIhYvtHrel%2BMYIO%2BlIs%3D&reserved=0

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20200722/ff99b0f9/attachment.html>