Thanks for the reply, I am not sure what do you mean by the basis set size but if you mean the density mesh cut-off, I tried for two different values (150 Rydberg and 18 Rydberg). the followings are more details about what I am doing:
1. I want to be able to calculate the Mulliken net charge for a C59Pt molecule.
2. these are some parameters that I used in my calculation: LDA , DiracBloch exchange and VoskoWikiNussairRPA correlation.
3.In my calculation the Mulliken charge for Pt atom is 9.893 for 150Ry and 9.863 for 18 Ry that means the net charge of 0.107 and 0.137 respectively, while this value in literature is much larger ( 0.618-1.3)
BTW, would you please explain why the change in the density mesh cutoff value can change the final result and what do you think is the suitable value for this system
Thanks!