Multiwfn forum

rikaaardoss

Member

Registered: 2020-07-29

Posts: 22

regarding conceptual dft analysis and "orbital weighted" indicators

Greetings

When calculating the “Orbital Weighted” reactivity indices using Multiwfn depending on the system being studied and the delta value, it can deliver condensed (and grid) values of 0.0. I understand that this is related to the definition of the indicators, since the values are always very close to zero but there would be a way to “force” the program to calculate with a higher amount of decimals? maybe a modification in the settings.ini file? I know this could lead to a higher computational cost but I am willing to take the risk.

Thank you very much in advance.

R.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,830

Website

Re: regarding conceptual dft analysis and "orbital weighted" indicators

Hello,

I don't exactly know which data you are talking about, could you provide a screenshot?

Best,

Tian

rikaaardoss

Member

Registered: 2020-07-29

Posts: 22

Re: regarding conceptual dft analysis and "orbital weighted" indicators

I apologize for the lack of clarity, I mean specifically when calculating the grid for the orbital weighted dual descriptor and their respective condensed values, when I put a very small delta the values obtained are directly 0, for this reason I can not visualize the cubes in programs like chemcraft nor draw any conclusion with the condensed values.

Many thanks.

R.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,830

Website

Re: regarding conceptual dft analysis and "orbital weighted" indicators

I don't know why you intend to use a very small delta value, perhaps you only want to consider the contribution from the "most" frontier MO? If yes, you can gradually decrease the delta value from the default value 0.1 a.u., each time you can choose "5 Print current orbital weights used in orbital-weighted (OW) calculation" to check the weights.

Taking examples\benzene.fch as example, if the delta is decreased to 0.01 a.u., you will see the following output after choosing option 5

10 Highest weights in orbital-weighted f+
Orbital    22 (LUMO  )   Weight:  50.00 %   E_diff:     3.410 eV
Orbital    23 (LUMO+1)   Weight:  50.00 %   E_diff:     3.410 eV
Orbital    24 (LUMO+2)   Weight:   0.00 %   E_diff:     5.656 eV
Orbital    25 (LUMO+3)   Weight:   0.00 %   E_diff:     7.147 eV
Orbital    26 (LUMO+4)   Weight:   0.00 %   E_diff:     7.147 eV
Orbital    27 (LUMO+5)   Weight:   0.00 %   E_diff:     7.789 eV
Orbital    28 (LUMO+6)   Weight:   0.00 %   E_diff:     8.202 eV
Orbital    29 (LUMO+7)   Weight:   0.00 %   E_diff:     8.202 eV
Orbital    30 (LUMO+8)   Weight:   0.00 %   E_diff:     8.389 eV
Total weight of above listed orbitals: 100.00 %

10 Highest weights in orbital-weighted f-
Orbital    21 (HOMO  )   Weight:  50.00 %   E_diff:    -3.410 eV
Orbital    20 (HOMO-1)   Weight:  50.00 %   E_diff:    -3.410 eV
Orbital    19 (HOMO-2)   Weight:   0.00 %   E_diff:    -5.924 eV
Orbital    18 (HOMO-3)   Weight:   0.00 %   E_diff:    -5.924 eV
Orbital    17 (HOMO-4)   Weight:   0.00 %   E_diff:    -6.498 eV
Orbital    16 (HOMO-5)   Weight:   0.00 %   E_diff:    -8.011 eV
Orbital    15 (HOMO-6)   Weight:   0.00 %   E_diff:    -8.011 eV
Orbital    14 (HOMO-7)   Weight:   0.00 %   E_diff:    -8.639 eV
Orbital    13 (HOMO-8)   Weight:   0.00 %   E_diff:    -9.084 eV
Orbital    12 (HOMO-9)   Weight:   0.00 %   E_diff:   -10.752 eV
Total weight of above listed orbitals: 100.00 %

Clearly, now only the degenerate two HOMOs and the two LUMOs contribute to orbital weighted Fukui function or dual descriptor.

Best,

Tian