[QE-users] For constant potential simulation in pw.x

[Minoru Otani]

Dear Xuan,

Thank you for your question.

First, regarding FCP: FCP is indeed a method for performing constant-potential simulations in pw.x. Example inputs for this functionality are provided in the Quantum ESPRESSO distribution under
examples/ESM_example.
You can run these sample calculations using the script run_example_FCP, which demonstrates how constant-potential simulations are performed within the ESM framework.

As for the solvent-related functionality, Quantum ESPRESSO supports hybrid DFT–solvent calculations based on the reference interaction site model (RISM), which is rooted in classical liquid theory. Using this approach, it is possible to combine DFT calculations in QE with a statistical-mechanical description of the solvent.

Sample inputs for these features are available in
examples/RISM_example.
This directory includes examples for:
 • 3D-RISM calculations, which treat molecules or ions dissolved in a solvent, and
 • ESM-RISM calculations, which enable simulations of electrochemical half-cells at electrode–electrolyte interfaces.

These examples can be executed using the scripts run_example_3D-RISM and run_example_ESM-RISM, respectively.

I hope this clarifies where to find the relevant examples and how to get started with these functionalities.

Best regards,
Minoru
--------------------------------------------------------------------------------------------------------
Minoru Otani, Ph.D., Professor
Center for Computational Sciences and Faculty of Pure and Applied Sciences, 
University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
E-mail: otani at ccs.tsukuba.ac.jp
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> On Dec 24, 2025, at 17:24, ww <garrettwx at 163.com> wrote:
> 
> Dear all,
> 
> I am now noticing the function for performing constant potential simulation in pw.x with the Tag of FCP and SOLVENT, 
> 
> However, I have not found the related examples for this function. 
> 
> And one users can provide me with the detailed tutorials?
> 
> Thank you very much.
> 
> Best regards,
> Xuan
> 
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