Hello,

I have not done this specific calculation, but I have calculated the properties of electrides which have dissociated electrons living in the empty cavities of a crystal structure, which is a fairly close equivalent in the solid state.

There are two ways that I know of to do this kind of calculation. One is to have a charge-neutral cell with the electron spontaneously dissociated from its parent atom, which is how the electrides worked. For example if the solvent is protic, like NH3, you could try adding an extra hydrogen to the cell full of NH3 and hope that the electron dissociates and forms a solvation shell of NH3 atoms. If this doesn't work, you could try setting the NELECT tag to add one extra electron, compensated by a uniform background charge, but this may be less physically realistic.

In either case, you unfortunately can't control the electron's location directly; the best you can do is manually arrange a shell of solvent atoms around a void space to create a region of favorable potential, and hope the electron decides to live there. It is not necessary to modify the POTCAR for either method.

Hello Steven,

Thank you for your response. My system is an electron surrounded by water. So, your second suggestion worked for me, where I removed the electron from POSCAR and added one electron to the system through NELECT. Thank you so much!