Solvation energy of monatomic metal ion

[YY-Hsu-m23]

Hi,

I used VASPsol to calculate the solvation energies of metal cations (including Co2+, Fe2+, Ni2+, Ag+) and metal atoms (Cu). I created a model with a box size of 20Å and the ion in the center of the box. The following is an explanation based on the INCAR file of Co2+. The ions were charged by NELECT and corrected by IDIPOL. However, calculations with the same parameters will produce different results, and most calculations cannot be self-consistent in electronics. Even if self-consistency is achieved, the total energy of the system will have different results, and none of the results are close to the solvation energy values in the literature, all models have this situation. Being new to first principles calculations, I had no idea what problems I was facing. I hope to receive your suggestions and tips for my questions. If you need more information, let me know.

Best Regards,
Hsu

INCAR file of Co2+

ALGO = Fast
ISMEAR = 0
SIGMA = 0.05
NELM = 100
EDIFF = 1E-7
PREC = Accurate
IBRION = -1
ISPIN = 2

NELECT = 7
LDIPOL = .TRUE.
IDIPOL = 4
DIPOL = 0.5 0.5 0.5

LSOL = .TRUE.
EB_K = 78.4

[rhennig]

Hi YYHsu-m23, Your overall procedure seems reasonable based on your description. To help with convergence, you need to increase the cutoff energy of the plane wave basis significantly over the default value. Try something like 800 eV, possibly even higher for some of your ions. Since some of your cations are quite small and highly charged, they will have high fields in their vicinity. In that case, the linear solvation model may be inadequate and lead to a screening that is too high. Also, in your plots, do you show the energy difference between the charged ion and neutral atom? Best regards, Richard — Richard G. Hennig Professor and Alumni Professor of Materials Science and Engineering Associate Director, Quantum Theory Project Department of Materials Science and Engineering, University of Florida Email: ***@***.******@***.***> Web: http://hennig.mse.ufl.edu<http://hennig.mse.ufl.edu/> From: YYHsu-m23 ***@***.***> Date: Wednesday, December 18, 2024 at 4:06 PM To: henniggroup/VASPsol ***@***.***> Cc: Subscribed ***@***.***> Subject: [henniggroup/VASPsol] Solvation energy of monatomic metal ion (Issue #102) [External Email] I used VASPsol to calculate the solvation energies of metal cations (including Co2+, Fe2+, Ni2+, Ag+) and metal atoms (Cu). I created a model with a box size of 20Å and the ion in the center of the box. The following is an explanation based on the INCAR file of Co2+. The ions were charged by NELECT and corrected by IDIPOL. However, calculations with the same parameters will produce different results, and most calculations cannot be self-consistent in electronics. Even if self-consistency is achieved, the total energy of the system will have different results, and none of the results are close to the solvation energy values in the literature, all models have this situation. Being new to first principles calculations, I had no idea what problems I was facing. I hope to receive your suggestions and answers to your questions. If you need more information, let me know. INCAR file of Co2+ ALGO = Fast ISMEAR = 0 SIGMA = 0.05 NELM = 100 EDIFF = 1E-7 PREC = Accurate IBRION = -1 ISPIN = 2 NELECT = 7 LDIPOL = .TRUE. IDIPOL = 4 DIPOL = 0.5 0.5 0.5 LSOL = .TRUE. EB_K = 78.4 image.png (view on web)<https://github.com/user-attachments/assets/ccc67bd9-74dc-446a-bef3-b9c7898f3cef> image.png (view on web)<https://github.com/user-attachments/assets/645be9b2-3aad-4fc1-b85a-b534e3f2748f> — Reply to this email directly, view it on GitHub<#102>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ACCOT2UKSATCZ2XUNLIKDXD2GHPT5AVCNFSM6AAAAABT3RV4PKVHI2DSMVQWIX3LMV43ASLTON2WKOZSG42DQNZUHE3DSNY>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>