Multiwfn forum

Dear Tian,
Please suppose a given "WFN" file is at hand. Is there any way to find which "method/basis set" is employed to generate such a file? Usually, this information is not included in a generated "WFN" file.

Sincerely,
Saeed

Dear Tian,
Recently, I studied PnB interaction in O2IPn...NCH systems (Pn= N, P, As, Sb, Bi). While, as many previous experiences, it is expected a satisfactory linear correlation exists between values of Rho at BCP and values of interaction energies, in the case under study, this correlation displays a very poor R*R value. On the other hand, a much more satisfactory correlation is obtained between values of interaction energy and Laplacian of Rho! I also found that the main problem is caused by two heaviest elements Sn and Bi. Indeed, if data associated with these two elements are removed from any regression, the resulted regression is highly improved.

Could you please let me know your highly professional explanation about such a strange and novel observation?

Sincerely,
Saeed

Dear Tian,

When a given atom uses PP basis set, Gaussian takes a specific number of electrons as core electrons. For instance, using aug-cc-pVDZ(+PP) basis set for Iodine atom, Gaussian indicates that 25 electrons out of total 53 electrons are taken as valence electron for Iodine. In consequence, 53-25=28 and, one can conclude that the number of core electrons in Iodine approximated by a PP basis set is 28. The question (which is in my mind for a long time) is that this 28 electron should be regarded as small-core, medium-core, or large-core? Commonly, after computing the number of core-electrons as shown for Iodine, how one reliably should identify small-, medium-, or large-core size regarding the core electrons in a desirable atom?

Moreover, please also let me know how much a given "grac_shift" value in the DFT-SAP should be accurate. Indeed, while some researchers consider only two digits after the decimal point (XX.YY), other ones take 4-5 digits after the decimal point (XX.YYYY or XX.YYYYY) for a given "grac_shift" value.

In advance, many thanks for your kind attention and highly valuable guidance.

Sincerely,
Saeed

Dear Tian,

1- Please suppose one is going to perform ESP analysis (main function 12) on a "chk" file generated with "genecp" in which some atoms use PP basis sets. Please let me know if ESP analysis is quite correct and reasonable in such cases. If there is any problems, please let me know appropriate technical procedure.

2- Please also let me know what is the difference between "ESP from nuclear charges" and "ESP from electrons". What is the sum and difference of these two quantities referred to, respectively, if such sum or difference is conceptually meaningful?

Sincerely,
Saeed

Dear Tian,

As you know much better than me, a DFT-SAPT needs "grac_shift" values for monomers. Please consider the below template employed for a given DFT-SAPT calculation:

memory 55 gb

molecule {
0 1
F                  0.00000000    0.00000000   -1.85087700
H                  0.00000000    0.00000000   -0.86870700
--
-1 1
Cl                 0.00000000    0.00000000    1.03097600

units angstrom
no_reorient
symmetry c1
}

set {
    basis aug-cc-pVTZ
    df_basis_scf  aug-cc-pvtz-jkfit
    df_basis_sapt aug-cc-pvtz-ri
    scf_type DF
    guess sad
    freeze_core True
    sapt_dft_functional pbe0
    sapt_dft_grac_shift_a 0.157
    sapt_dft_grac_shift_b 0.215
}

energy('sapt(dft)')

The question is as follows:

the "sapt_dft_grac_shift_a" is always regarded to the monomer whose structure is given first (HF in the present case) and "sapt_dft_grac_shift_b" is always regarded to the monomer whose structure is given second (Cl anion in the present case). Is my statement quite correct?

If no, we should properly define monomer a (for which grac_shift_a is considered) and monomer b (for which grac_shift_b is considered). If possible, considering the given template, please let me know how these two monomers should explicitly and appropriately be defined in two blocks.

Sincerely,
Saeed

Dear Tian,
If possible, please let me ask you a short question in SAPT-DFT:
To obtain DFT_Grac_Shift value for two interacting monomers, I am using PBE0/def2-TZVPPD level to optimize monomers geometry (and to obtain HOMO energy) and also to compute Vertical IP value. Then, DFT_Grac_Shift (in a.u.)= VIP(in a.u.)+E_HOMO(in a.u.).

Please let me know if you completely agree with the computational level I employed for mentioned purposes.

Sincerely,
Saeed

Dear Tian,

There are many nice and highly informative article in your homepage; e.g. "//www.umsyar.com/413" or "//www.umsyar.com/526", etc. These articles are highly valuable but there is no an ordered and regular list for this articles by which one can easily find the desirable topic. Could you please let me know where I can find all these articles in a regular and integrated manner?

Sincerely,
Saeed

Dear Tian,

If possible, please let me ask you a short question regarding Psi4.
Recently, I lost my Psi4 code and had to again install its newest version 1.9.1 through "Conda-Forge". Moreover, I did build a scrath folder for Psi4 in the Home directory and its path was truly included in ".bashrc". When a given Psi4 task is ran, this folder is filled and empty alternately. But, after finishing calculations, this folder remains full and there are several files in it that must be deleted manually, while there was no such problem before. Please also let me state that the problem mentioned above only exists for "CBS-extrapolations" calculations while "SAPT" calculations are never encountered such a problem.

Could you please let me know how I can resolve this problem so that this folder, when a task is over, to be emptied automatically as before?

In advance, too many thanks for your highly valuable guidance.

Sincerely,
Saeed