UT theoretical chemistry code forum

Dear All,
First, thank you, thank you, thank you.... wonderful utilities to use with VASP. It is very kind of you to make them available.

Second, I am a new user of bader, and only a recent VASPer, so please forgive my stupid questions.

I have built a version of VASP4.6 with the bader extensions and the pDOS extensions from your website.
I am trying to calculate a bader pDOS.
I am unsure how to correctly combine the advice from various pages of the website.

The steps I have taken are
(1) calculate AECCAR0(12)
(2) do a bader analysis to generate AtIndex.dat (BDRCAR)
(2a) use the utility chgsum.pl AECCAR0 AECCAR2 which generated CHGCAR_sum as a reference file...
(2b) use the program bader to generate AtIndex.dat. Here I am confused. I think I need to run bader with the following options
(combining advice from bader page for VASP and DOS page):
-vac,
-ref CHGCAR_sum,
-p atom_index
I can use the following syntax:
bader -p atom_index CHGCAR -ref CHGCAR_sum
which appears to work, but I cannot find a way to specify -vac as well as the other options....

Please tell me how to use -vac for a VASP bader analysis of this kind, or if I'm misguded, please tell me how to do the calculation properly.

All help will be most gratefully received..
Thank you for your time... Iain

That looks very close. Try adding an argument to the -vac flag:

bader -p atom_index -ref CHGCAR_sum -vac auto CHGCAR

You can also specify a charge density value as the vacuum cutoff instead of using the default value. Or you can skip the -vac flag, but if you have a lot of vacuum in your system, you will find a lot of unoccupied levels in the DOS for atoms adjacent to the vacuum (for example, at the surface of a slab).

Thank you very much for your help. I greatly appreciate it.
best regards... Iain