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Hello Developers,
I am Sourav Rudra, PhD student from JNCASR, India. I am a beginner of VASP. Currently for one of my projects. I have used VASP. But I have found some issue with Scf convergence to my system. The system has 4f electrons. I have tried both VASP-6.3.2 and VASP-5.4.4 to converge my system with 40 cores and NCORE=4 in INCAR. The Scf is converged in version 5.4.4 but it is not converged for version 6.3.2. For version 6.3.2 some time it converges some time it not. I can not find any way to resolve it. I am not understand why the Scf is converged in Vasp 5.4.4 but not in 6.3.2. I have attached results of both version here as tar file. Please find the attachment here. Also At the time of bands calculation using the CHGCAR of converged Scf calculation I am getting to much of stress in bands OUTCAR file, But Scf OUTCAR showing stress of 0.3 kb but bands OUTCAR prints stress 12097 kb. I am not getting this point why the stress is too much high in bands calculation but Scf shows a small stress indicating relaxed structure. Also, with reducing SIGMA, the Scf is not converging in version 5.4.4 also. The system is converged for SIGMA=0.05 and ISMEAR=0 in version 5.4.4.
Please help me regarding this issue. I am looking forward for your answer.

Thanks with best regards,
Sourav Rudra

Dear Sourav Rudra,

Thank you for bringing this issue to our attention. We are looking into it and will provide feedback as soon as possible on the issue of the convergence with Vasp 6.3.2.

Regarding the stress, I am not sure that one should compare the results from stress coming from an SCF calculation vs a bands calculation, and most likely it will be wrong in the second case due to differences between the setups in both calculations, e.g. different sampling of k-points in the SCF (regular grid) and bands calculation (path). I will come back to you with a clearer answer.

Kind regards,
Pedro Melo

Hello Pedro Melo,
Thanks for your reply regarding this issue. I will need another help regarding this. Actually I am trying to calculate the DOS of this Yb rare earth compound (particularly position of 4f orbital in +3 oxidation state), which shows two oxidation state +2 and +3. I am using VASP_PAW PP for this. Now, there are three available PP like Yb, Yb_2 and Yb_3. Among them only Yb contains 4f14 in the valence electron which gives +2 oxidation state of Yb , others (Yb_2 and Yb_3) do not contain Yb 4f in the valence electron, But to get +3 oxidation state i need 4f146s25d1 valence electron configuration based PAW PP in VASP. This sort of PP is not available in VASP. Can you please provide me some information how can i get this sort of PP or can i generate it in VASP?

I will look forward to your answer.

Thanks with regards,
Sourva Rudra