Grand-canonical electronic energy

[liam3935]

Hi All,

I have a question regarding the grand-canonical electronic energy calculations proposed in https://pubs.aip.org/aip/jcp/article/151/23/234101/315578/Implicit-self-consistent-electrolyte-model-in. I'm wondering if geometry optimization is needed for each of the calculation set at different potential by NELECT? If so, will the quadratic behavior still hold if structure changes significantly?

Thanks,
Liam

[foster362]

You will get a different answer if you optimize with the solvation model turned on; how different depends on your problem/system. For example, there will not be much of a difference on a small molecule or a surface; however, a water molecule on a metal surface can change orientation with potential. In the former case, you will see the quadratic behavior even if optimizing. In the ladder, you will likely get a discontinuity or at least the quadratic behavior will break when the geometry changes. If the geometry doesn't change, the quadratic behavior will hold, so it depends on your system and the potential range that is considered.

[andyscratch]

can you help me with performing constant electrode potential calculation using vasp?

[foster362]

Use VASPsol++On Sep 18, 2024, at 8:14 AM, andyscratch ***@***.***> wrote: can you help me with performing constant electrode potential calculation using vasp? —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you commented.Message ID: ***@***.***>

[andyscratch]

yes that is what I want to use. Please I want the guidelines of setting the INCAR file. How to set the constant potential and vary the number of electrons. I am new to this. Your help would be deeply appreciated

[foster362]

Not VASPsol, use VASPsol++. This new version has the ability to do fix potential calculations. All of the input variables are discussed (https://gitlab.com/cplaisance/vaspsol_pp). Sent from my iPhoneOn Sep 18, 2024, at 2:23 PM, andyscratch ***@***.***> wrote: yes that is what I want to use. Please I want the guidelines of setting the INCAR file. How to set the constant potential and vary the number of electrons. I am new to this. Your help would be deeply appreciated —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you commented.Message ID: ***@***.***>

[andyscratch]

Ok. I think I'm not explaining myself well. I want to plot electrode potential against surface charge density and also determine the potential of zero charge. I know I can use VASPsol++ but I want guidelines. Like steps to accomplish it. I'm new to solvation modeling. I only found it online and I've read the paper over and over again.

…

On Wed, 18 Sep 2024 at 2:00 PM, foster362 ***@***.***> wrote: Not VASPsol, use VASPsol++. This new version has the ability to do fix potential calculations. All of the input variables are discussed ( https://gitlab.com/cplaisance/vaspsol_pp). Sent from my iPhoneOn Sep 18, 2024, at 2:23 PM, andyscratch ***@***.***> wrote: yes that is what I want to use. Please I want the guidelines of setting the INCAR file. How to set the constant potential and vary the number of electrons. I am new to this. Your help would be deeply appreciated —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you commented.Message ID: ***@***.***> — Reply to this email directly, view it on GitHub <#80 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADRLMNOPJJZZFCHYSD2GSNDZXHEVJAVCNFSM6AAAAABONRSVOSVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTANRYGUZTANI> . You are receiving this because you commented.Message ID: ***@***.***>