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Dear Tian,
Too many thanks for your highly valuable and informative comments.
Sincerely,
Saeed
Dear Tian,
If possible, please let me know the exact definition and concept of "electron density" and "spin density" and, their usage and relation regarding reactivity of a whole molecule or a specific site in a given molecule. You may also introduce a nice reference regarding these concepts and their usage.
PS. I am still waiting your valuable replies to my emails which were sent to you three days ago. Such a situation has no precedent and, indeed, I am worry about your health, my nice friend.
Sincerely,
Saeed
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
Dear Tian,
OK. As you nicely indicated, I will try it but I am waiting your definitive reply after 2th Jun, as you mentioned.
Sincerely,
Saeed
Dear Tian,
Thank you very much.
Indeed, considering the x,y, and z coordinates of two carbon atoms of acetylene we can find coordinates of mid point as:
X=(x1+x2)/2, Y=(y1+y2)/2, and Z=(z1+z2)/2. Then, we can put a Bq atom at this point and calculate the value of "the closest distance to the point" for this Bq by entering its index. Do you confirm the validity of my approach?
Sincerely,
Saeed
Dear Professor Lu,
Too many thanks for your kindness to share your highly important, valuable, and informative explanations.
Sincerely yours,
Saeed
Dear Professor Lu,
First of all, please let me say you merry Christmas and happy new year 2020; I wish you and your honorable family all the best.
If you kindly let me, I would like to ask a question regarding calculating mutual penetration. Please, suppose the XB (halogen-bond) interaction between F-Cl and the pi-system of acetylene in a T-shape approach: F-Cl...HCCH. When we are going to calculate the value of mutual penetration between Cl and pi-electrons of acetylene in the corresponding dimer complex, we also need the vdw radius of acetylene pi-electrons in its isolated and fully optimized structure. While this quantity can easily be calculated for Cl atom (through sub-function 10 of main-function 12) how should this value be calculated for the acetylene pi-system while, in this case, we have no a certain atom?
In advance too many thanks for your kind attention.
Sincerely,
Saeed
Dear Tian,
Thank you very very much.
Sincerely,
Saeed
Dear Developers,
In the manual of Multiwfn is it evidently indicated that the default value of "cubegendenstype" is "SCF".
In this regards, I have been encountered with a problem when I am going to calculate electrostatic potentials. Please let me explain my problem with a simple example:
Suppose that a given molecular system has been optimized at the MP2/6-31G(d) computational level and I want to calculate value of (V_s,max) on a specific atom using MP2 density. As far as I know, two possibilities exist:
1- In the "settings.ini" file, the value of "cubegendenstype" is changed to MP2 and, then, upload the ".chk" file generated within optimization to the Multiwfn and attempt to calculate V_s,max through main function 12.
2- The value of "cubegendenstype" in "settings.ini" is left unchanged (the default "SCF" is kept). Then, try to generate a "wfn" file for the fully optimized structure using "MP2/6-31G(d) out=wfn density=current" command line. Then, the generated "wfn" file is uploaded to Multiwfn and attempt to compute value of V_s,max through main function 12.
While it is expected that both of two above-mentioned procedures should lead to an identical value of V_s,max I am looking for, procedures 1 and 2 lead to the two different values for V_s,max. If possible, please kindly let me know what is the problem and which one of procedures 1 and 2 should be taken into account.
In advance, your kind attention is highly appreciated and I hope you can reply to my message soon as much as possible.
Sincerely,
Saeed