bulk MgO

[khonkala]

Dear Depelopers,

When I run the bader program for bulk MgO using cube files created by dacapo,
I obtain:
# X Y Z VORONOI BADER % MIN DIST
------------------------------------------------------------------------------------------
1 0.0000 0.0000 0.0000 6.9072 6.2948 11.2407 1.4523
2 4.0629 4.0629 0.0000 6.9072 6.2948 11.2407 1.5006
3 4.0629 0.0000 0.0000 7.0929 7.7308 13.8049 2.0775
4 0.0000 4.0629 0.0000 7.0929 7.7311 13.8054 2.0775
5 0.0000 0.0000 4.0629 7.0929 7.6977 13.7458 2.0775
6 4.0629 4.0629 4.0629 7.0929 7.6614 13.6810 2.1637
7 4.0629 0.0000 4.0629 6.9072 6.2948 11.2407 1.5006
8 0.0000 4.0629 4.0629 6.9072 6.2948 11.2407 1.5006

So it looks as if O atoms have obtained only approximately 0.3 electrons.
I used 8 and 6 electron pseudo potentials for Mg and O,
respectively. (Please see details
http://oldwww.fysik.dtu.dk/CAMPOS/Docum ... index.html)

Do you have any idea what I can do to get more reasonable results for MgO ?

Best regards,
Karoliina

[graeme]

A charge of 0.3 does seem low.

I'm taking a guess here, but it is possible that your your first two and last two atoms are Mg, which had a valance of 8, and the middle four are the O atoms with a valance of 6? If so, this would give you charges of +1.7 for Mg and -1.7 for O.

[khonkala]

Hi !

Thanks for the tip ! You are right. I checked atom types once but obviously I made a mistake and therefore I tought that the charge transfer is only 0.3 electrons/atom.

Best regards,
Karoliina