Hi,
I am trying to run the bader analysis, and I am curious what the difference between the CHG and AECCAR2 - it seems as they both contain the valence density. Also, why do I need to reference the AECCAR0+AECCAR2 sum instead of just being able to run the bader analysis on the CHGCAR_sum file?
Thank you
Bader analysis with core charges in VASP
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Re: Bader analysis with core charges in VASP
I don't know if there is a difference between CHG and AECCAR2; they may be the same.
The reason to use the total charge as a reference system to define the Bader volumes, but then do the analysis only on the valance electrons is because of the cusp in charge density at the atomic cores. We found that you need an extremely fine grid in order for the total charge density to integrate to the total number of electrons (including the core electrons). The problem is with resolving the charge density peaks at the nuclei. But this plays no role in the location of the Bader surface or in the valance charge distribution, which is generally the quantity of interest. So we found that it works well to find the Bader volumes using the total charge, but then integrate the valance charge in these volumes.
The reason to use the total charge as a reference system to define the Bader volumes, but then do the analysis only on the valance electrons is because of the cusp in charge density at the atomic cores. We found that you need an extremely fine grid in order for the total charge density to integrate to the total number of electrons (including the core electrons). The problem is with resolving the charge density peaks at the nuclei. But this plays no role in the location of the Bader surface or in the valance charge distribution, which is generally the quantity of interest. So we found that it works well to find the Bader volumes using the total charge, but then integrate the valance charge in these volumes.