[Wien] convergence of Bader (aim) calculations

[Peter Blaha]

Also my experience with Bader is limited, but:

I usually trust charges to about 1-3 hundreds of an electron (X.yz+/-0.03)



>Rkmax is really important - at rkmax 7 (for RMT(C)=1.3 and RMT(K)=1.45, approximately) I am starting to see (I hope :)) signs of convergence.  Unfortunately I doubt I'll be able to go significantly beyond 7.


K seems a little bit small. Anyway, what means "convergence" ? To how many
digits in the charge ? I'm surprised that you need to go that high with
RKmax.

> 1/ which values of the named parameters would you expect to be reasonable?  I'm especially interested in hearing about nth,nphi and npr - perhaps an increase of merely 10 points is ridiculously small?  (I'm sampling the full interval, by the way - I'm not using symmetry there).

More or less use the defaults. Within my accuracy (above) it should be ok.

I always check the integration by forming the sum of all charges*mult !! and
this must be close to zero. (with charges I mean the last number in the
outputaim file). This worked also (within 0.05) for 88 atom cells.

If it is not, the only explanation could be, that your structure is so open
(and with a very low density) that aim has problems,
or it would also be explained when you have a non-nuclear maximum in the
density (like an F-center).

                                     P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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