a question about the source code to define the broadening function in ATK

[Roc]

Dear Dr.
     when I try to understand the NEGF+DFT of ATK deeply,  I notice some different definitions on the broadening function.  following Eq.1 (Phys. Rev. B 65, 165401 (2002)) is same to Eq.2(J. Phys. Chem. C 2008, 112, 1685 1693), another Eq.3(PHYSICAL REVIEW B, VOLUME 64, 115411) is different. I want to konw which Eq is correct for the source code compiled in ATK.
thanks.

[Anders Blom]

These expressions are actually equivalent (except the factor 2, which probably is a spin degeneracy) since GA = (GR)+ in the non-interacting case.