Multiwfn forum

saeed_E

Member

Registered: 2019-12-21

Posts: 237

Questions regarding energy decomposition through extralink 608 by G16

Dear Tian,
I hope you are doing well and all is going best with you.

Please consider the below Gaussian route:

#P b3lyp/6-31g* Extralinks=L608

I also have included -5 5 (minus five-space-five) at the end of the molecular specification after a blank line. The part of output I am looking for is as follows:

ET= 138.677437 EV= -438.305045 EJ= 122.475098 EK= -18.233408 ENuc= 56.268500

A=0 I= 1 IExCor= 402 IRadAn= 5 ScaHFX= 0.200000
ScaDFX= 0.800000 0.720000 1.000000 0.810000
HFx= 0.000000 0.000000 1.000000 0.000000 0.000000
DFx= 0.000000 0.000000 1.000000 0.000000 0.000000
DFc= 0.000000 0.000000 1.000000 0.000000 0.000000
ENTVJ= -120.884010 Ex= -18.153704 Ec= -0.933250 ETotM2e= -258.7993810258 ETot= -139.9709643500

If you kindly let me, I am going to ask some question as follows:

1- It is known that: Ex: Exchange term = EK * ScaHFX + DFT-Exchange * ScaDFX. Thus, one can write: DFT-Exchange energy=[Ex-(EK * ScaHFX)]/ScaDFX.
While the value of ScaHFX is characterized with only one number (here, 0.200000), several numbers (as, 0.800000 0.720000 1.000000 0.810000) are given for ScaDFX. Consequently, if one wants to compute value of DFT-Exchange energy based on the equation mentioned above, which of these numbers should be considered for ScaDFX?

2- The value of E_Tot (SCF energy), defined as ET + EV + EJ + Ex + Ec + ENuc which in this case is -139.9709643500 must be equal to the value of HF-energy which is always taken as the total electronic energy of the given system and, in this case is E(RB3LYP) = -139.970964347. Is my statement quite correct? Please be aware that I did perform another calculation using M06-2x/aug-cc-pVTZ level and include (-55 5) at the end of molecular specification but, surprisingly, a significant difference by ca. 2 kcal/mol was found between these two energy values! Could you please let me know the origin of such a difference?

3- What is the meaning of "ETotM2e" whose value in the current case is -258.7993810258?

In advance, your kind attention is highly appreciated and please accept my deepest apology for taking your valuable time, my nice friend.

Yours sincerely,
Saeed

Last edited by saeed_E (2023-03-01 03:52:10)