UT theoretical chemistry code forum

Hellow,

I have used your developed bader program to investigate diamond Si system.
Without the core charge density, I obtained the reasonable value for Si whose value is 4 just printed in ACF.dat. However, if I visualize the corresponding BvAt file in 3d graphs, there appears shaggy charge density. Therefore, according to the instruction for vasp, I changed the main.F routine. Then I can get the reasonable 3d graphs. However, the Bader charge printed in ACF.dat is more than 4 values. It seems that these values are not adequate.

However, if I test the sample for NaCl, I can obtain the reasonable without added partial core correction. And bader charge printed in ACF.data is reasonable one. And I think that for Cl one need to add the partial core correction.

With best regards

We don't really understand when the changes in main.F add partial core charges and when they don't. For silicon, an extra (roughly) 1.1 electrons are added per atom. To do the Bader analysis, you need to calculate a single Si atom to know what the total charge on Si is. This should be close to 5.0938. This value has the 4 valance electrons, and 1.0938 electrons in the core region.

No core charge is added for Na or Cl using the modification in main.F. You can use the Na_pv or Na_sv to include more core electrons explicitly.

Rough surfaces around the Bader volumes can be improved by increasing your grid size. This can be done by setting NGXF, NGYF, and NGZF in the INCAR file. Usually doubling them from the default values in your OUTCAR file is a good first guess for a fine grid.