What Are Integral Centers in Hartree Fock Theory?

[greisen]

Hi,

I am looking at the integrals in HF - I am a little puzzled about the use of the word center.

F.ex. two electron integrals on different center - it that electron belonging to different atom A and B?

Than it mentions three- and four center - how to interpreted center?

Thanks in advance

best regards

 

[greisen]

Hi,

I guess that centers are often atom coordinates when using gaussian functions but it is not necessary atomic coordinates when using Slater functions?