I have replied you via E-mail.

Dear Professor Lu,

Please suppose an I...N XB interaction. The value delta_g^IGM calculated at the BCP of this interaction using sub-function 7 is 0.0158 a.u.
On the other hand, values of atoms delta_g index (delta_g N and delta_g I) as well as those of atoms pair (delta_g N/I) are ten times greater in magnitude than above-mentioned value (0.0158 a.u.). Thus, to have a complete consistency, it seems all values printed out in the "atmdg.txt" file are already multiplied by 10 and we should divide them by 10 prior using.

Do you agree with me?

If no, how do you explain such a very large difference in magnitude? Indeed, the value of delta_g^IGM is ten times lower in magnitude than the values reported in "atmdg.txt" file. In other words, value of delta_g^IGM is in power of 10^-2 while those in "atmdg.txt" are in power of 10^-1, displaying a difference by 10^1 which seems non-reasonable.

On the other hand, when we attempt to calculate value of delta_g^IGM at the BCP of a given NCI through sub-function 7, this value corresponds to the sum of delta_g^inter and delta_g^intra exactly at the BCP and, as was indicated, this value can reasonably be associated with only delta_g^inter at BCP. When the values of atoms delta_g (values corresponded to the contribution of each atom) are summed together, the resulted value is considerably larger than the value of delta_g^IGM at BCO since the mentioned summation reflects the contribution of all atoms within all possible NCIs (constructive and destructive) between two monomers while delta_g^IGM only reflects the constructive interaction exactly at the BCP.

Do you agree with my understanding?

And finally:

As you nicely recommended, I attempted to calculate exact value of delta_g^inter at the BCP of a given NCI using the generated "dg_inter.cub" file.

Initially, I generated the ".wfn" file and within calculation of IGM and generating delta_g^inter the exact electron density (SCF density) was selected not the promolecular one. The "iuserfunc" was also changed to -1 in "settings.ini" file.

When I loaded generated delta_g^inter to extract the value printed out for "User-defined real space function" corresponded to the value of delta_g^inter at the BCP of given NCI, the following message was also observed on the Multiwfn window:

"Note: The loaded file does not contain wavefunction information, below results are evaluated from promolecule density".

As I mentioned, I employed a ".wfn" file within calculations. So, why is such message observed indicating program uses promolecular densities?

Yours sincerely,
Saeed