Non-zero vacuum charge in v0.95

Bader charge density analysis

Moderator: moderators

Post Reply
foobar
Posts: 3
Joined: Tue Mar 08, 2016 12:33 pm

Non-zero vacuum charge in v0.95

Post by foobar »

Hi,
using v0.95, i get non-zero vacuum charge for a neutral system computed with quantum espresso trying US/NC/PAW PBE potentials.
the cube file was created using pp.x. While i first thought that it was a problem with the fft grid, it turned out, that the old version of bader (0.28) gives the correct result. BTW, the number of electrons was correct in both versions.
graeme
Site Admin
Posts: 2256
Joined: Tue Apr 26, 2005 4:25 am
Contact:

Re: Non-zero vacuum charge in v0.95

Post by graeme »

Please check v0.95a which has a bug fix related to the vacuum change density.
foobar
Posts: 3
Joined: Tue Mar 08, 2016 12:33 pm

Re: Non-zero vacuum charge in v0.95

Post by foobar »

v0.95a gives also wrong results.
graeme
Site Admin
Posts: 2256
Joined: Tue Apr 26, 2005 4:25 am
Contact:

Re: Non-zero vacuum charge in v0.95

Post by graeme »

Please post the charge density files and try to describe the error as clearly as you can.

If you are saying that the problem is that the program gives you a non-zero vacuum charge density, then this might not be a problem. By default, the analysis will consider any cells with a charge density less than 0.001 e/Ang^3 into the vacuum region. This is useful for the analysis of gas phase species. If you would like to analyze all cells, you can use the "-vac off" setting or reduce the charge density value that is considered vacuum: "-vac 1e-5" , for example.
foobar
Posts: 3
Joined: Tue Mar 08, 2016 12:33 pm

Re: Non-zero vacuum charge in v0.95

Post by foobar »

Thank you very much for your reply. That was problem, in my case this led to a charge of roughly two e.
graeme
Site Admin
Posts: 2256
Joined: Tue Apr 26, 2005 4:25 am
Contact:

Re: Non-zero vacuum charge in v0.95

Post by graeme »

Ok, great. I should probably lower the default vacuum charge or leave this option off by default.
Post Reply