Hi, I am trying to understand the functional form of B3LYP from the Gaussian output file. I have tried to relate the details in the output file with the functional form of B3LYP. But I am not sure what certain terms correspond to. I have mentioned below the details. Can you pleaese help me. In the output of TD-DFT calculation files, I see the following (this is an e.g. of B3LYP) IExCor= 402 DFT=T Ex+Corr=B3LYP ExCW=0 ScaHFX= 0.200000 ScaDFX= 0.800000 0.720000 1.000000 0.810000 ScalE2= 1.000000 1.000000 And in this case, it is well known that the funcitonal B3LYP has 20% Hartree Fock Exchange and 80% Density Exchange, the terms ScaHFX= 0.200000 ScaDFX= 0.800000 which says the scaling factor for HFX is 20% and DFX is 80% respectively. And when summed up, they give the value '1'. 0.720000 corresponds to the coefficient for gradient of Ex(Becke88). Can someone please tell me what do the last two terms (1.000000 & 0.810000) correspond to. Please let me know if I am not clear.