UT theoretical chemistry code forum

I ran Bader with the example file for H2O (gaussian cube). The BCF.dat looks like this:
# X Y Z CHARGE ATOM DISTANCE
-------------------------------------------------------------------------
1 0.0000 -1.4362 0.9827 0.3766 3 0.0060
2 0.0000 0.0000 -0.1512 9.2510 2 0.0282
3 0.0000 1.4362 0.9827 0.3766 1 0.0059

I did the chelpg calculation in Gaussian with the same geometry and the partial charges turn out to be:
1 H 0.181065
2 O -0.362130
3 H 0.181065

The 9.25 charge for the oxygen doesn't make sense. Is there any conversion needed from Bader to Chelpg format?

The Bader charges reported by our program are the total number of electrons around that atom. Since O has a valence of 8, the net charge is -1.25. It is +0.52 on the two H atoms. Check with higher grid densities for convergence of these numbers (they should add to zero).

Is it the total number of electron or the valence electron? In the H2O case, I guess the total electron makes more sense. However, I tried the other example C2H4. The total electron in the ACF.dat is 12.000 which is 4*2+1*4. The valence electron is 4 for C but the total number is 6. It is a little confusing. Could you clarify this?

The Bader program reports the total number of electrons around each atom found in your charge density file. If you did an all-electron calculation, it will report the total number of electrons. If you did a calculation with only the valence electrons, it will report that number. There is no interpretation or analysis of these numbers in the Bader program -- it simply sums the number of electrons in your charge density file around each atom according to the Bader partitioning.