Page 1 of 1
Non-zero vacuum charge in v0.95
Posted: Tue Mar 08, 2016 1:39 pm
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.
Re: Non-zero vacuum charge in v0.95
Posted: Tue Mar 08, 2016 2:13 pm
by graeme
Please check v0.95a which has a bug fix related to the vacuum change density.
Re: Non-zero vacuum charge in v0.95
Posted: Tue Mar 08, 2016 2:20 pm
by foobar
v0.95a gives also wrong results.
Re: Non-zero vacuum charge in v0.95
Posted: Tue Mar 08, 2016 2:57 pm
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.
Re: Non-zero vacuum charge in v0.95
Posted: Tue Mar 08, 2016 3:10 pm
by foobar
Thank you very much for your reply. That was problem, in my case this led to a charge of roughly two e.
Re: Non-zero vacuum charge in v0.95
Posted: Tue Mar 08, 2016 3:16 pm
by graeme
Ok, great. I should probably lower the default vacuum charge or leave this option off by default.