Hi Sarita Ahlawat,

I don't know what kind of charge density data you have, but for CHGCARs obtained with VASP it works like this:

1.) You need 2 charge density files (CHGCARs) which have the same cell dimensions and the same grid. This is very important, because otherwise this method fails.

2.) Plot one of the charge densities by opening the file in VESTA

3.) Go to Edit -> Edit Data -> Volumetric data. There, you should see the currently plotted charge density file.

4.) Now import the second charge density file by clicking "Import..." and selecting the file. You can then choose from a list of operations which shall be applied to this file. Choose "Subtract from current data" to get the charge density difference.

I hope this is what you wanted to achieve.

Best regards,

Kai

Hi Kai Sellschopp

Thanks for your response..

I did the same steps as you described. But I am getting only positive differential charge density everywhere. It should be negative at some places, but everywhere it is coming positive only. Why this is happening? I am attaching my three CHGCAR-FeC, CHGCAR-Fe, CHGCAR-C,files here, I want to substract CHGCAR-Fe and CHGCAR-C from CHGCAR-FeC.

One more question from vesta, export charge density plot has no value on scale bar. How to get that?

Thanks

sarita

Hi sarita

I haven't used vesta to see the difference of the charge density but yes i have used vesta to calculate the spin density difference. Additionally You can use the software with the name "vaspkit" to directly calculate the charge density difference and later you can plot in vesta. I can attach the link to download the software:

https://sourceforge.net/projects/vaspkit/files/

Bests,

Monika

Sarita Ahlawat

When plotting 2D charge density surface, you can enter the minimum and maximum values which will provide a range to the scale bar. You can set the actual values as well as in terms of percentage. may be you need to give a negative value to the minimum. You can go through this paper to learn about charge transfer:Article Effect of solutes on ideal shear resistance and electronic p...

http://accelconf.web.cern.ch/AccelConf/srf2017/papers/thpb002.pdf

http://iopscience.iop.org/article/10.1088/1361-6668/aae147/meta

I plotted your file and I am able to see both charge accumulation and separation. The attached files will be helpful.

Kindly follow the link.

It is well described.

http://vaspnotes.blogspot.com/2013/10/charge-density-difference-plots.html

Also follow this tutorial.

Dear Pulkit and Mihir

Thanks a lot for your feedbacks. Now I am able to plot differential charge density for my system.

I have a few more questions:

1. How to define saturation levels min. and max. here. Is it same as Z(min) and Z(max)?

2. What should be scale bar values as vesta do not give those values during image exporting? ( will it be same again as Z(min) and Z(max)?)

3. How to calculate the units for charge density?

How to plot the charge difference on a specific bands?

Use:

LPARD = .TRUE.

Now:

LSEPK = .FALSE. # sum over all k-points if .FALSE.

LSEPB = .TRUE. # sum over all bands if .FALSE.

IBAND = 44 45 # band numbers

If you want charge density in some energy interval, instead of IBAND use:

NBMOD: with -2 if you want them to be specified with respect to the reference energy or -3 if your want them to be specified with respect to Fermi energy.

eg.

NBMOD = -3

EINT = 0.0 0.1

means print charge in the range [Ef,Ef+0.1eV].

I was also trying to plot charge density difference plot for my system in Vesta. But could not plot it. So I tried the above CHGCAR files FeC, Fe etc. But I could not get the plot as shared above @Pulkit Garg . Kindly help me to understand how to visualize both charge depletion and charge accumulation as shown above.

Hi,

The step by step procedure to perform the Bader charge analysis using VASP and charge density difference plot using VESTA is clearly explained in a Youtube channel. You can find it here:

https://www.youtube.com/watch?v=UxPrN7KcswA

https://bit.ly/2UtvbHE

Best,

Rasoul

the main point is to keep atom position steady in a heterojunction structure, and cauculate your junction and two other materials charge density respectively. then use vesta- edit date- volumetric date dialog to import your three charge density file. use the junction charge density to substract your two materials charge density.

This may be a naive question, but is the procedure the same when looking at alloys or intermetallics? For example, in this paper

https://iopscience.iop.org/article/10.1088/0953-8984/27/29/295401/pdf

the authors show charge density difference plots for Ni24Al7X (with X being some alloying element) as well as for Ni24Al8.

To create these plots, would I calculate a cell with 24 Ni atoms and 8 vacancies as one reference, one with 8Al (or 7AlX) as the other reference and then subtract the CHGCARs? Or what would be the procedure in this case?

i have plot of charge density but 2D plot are blank.can someone guide