Continuum solvation model with constant electrolyte concentration with different thickness about vaspsol

[ericfonseca95]

Hello Arindam,

The thickness of electrolyte on a surface is controlled by the electrolyte concentration, dielectric properties, and the applied potential. You can change the thickness (debye screening length) by modifying the L_EPSILON, LAMBDA_D_K, or by charging the surface and allowing the electrolyte to screen the charges. You can change the screening length without changing the concentration by modifying the L_EPSILON tag for dielectric properties and the NELECT tag for charging your system.

Eric Fonseca
Hennig Research Group

[Arindamsannyal]

Dear Eric Fonseca

Thank you very much for your kind information. But, unfortunately, I could not find any VASPsol document or example on how to set values for L_EPSILON tag in the INCAR file or how the L_EPSILON tag controls the electrolyte thickness without changing the electrolyte concentration. Is the L_EPSILON tag of VASPsol as same as the LEPSILON tag of the VASP software (e. g. LEPSILON=.TRUE. or .FALSE.)?

Thank you very much for your generous help.

Sincerely
Arindam Sannyal

[ericfonseca95]

Hello Arindam,

I apologize for the miscommunication in my last message. To change the dielectric properties of the bulk electrolyte in VASPsol is controlled by the EB_K tag. The default for this tag is EB_K = 80, which is the approximate dielectric constant of water. Be aware this is a material property and you should have data validating the dielectric properties of your solvent before proceeding with modifying EB_K for VASPsol calculations.

Eric Fonseca

[Arindamsannyal]

Dear Eric Fonseca

Thank you very much prompt response. In that case, I am afraid that using VASPsol, it is not possible to control the electrolyte thickness without changing the electrolyte concentration, am I right?

Thank you very much for your kind help.

Sincerely
Arindam Sannyal

[ericfonseca95]

Many factors determine the electrolyte thickness of the surface. Mainly the electrostatic potential, the concentration of electrolytes, size and shape of the ions, and temperature. These effects are summarized in the Debye screening length (LAMBDA_DK). Therefore, depending on the system you are studying, you must change LAMBDA_DK.

Eric