Multiwfn forum

amin.alibakhshi@hotmail.c

Member

Registered: 2019-08-25

Posts: 23

Evaluate contribution of energy from a single molecule

Hi everyone,
I am wondering, is there any possibility to evaluate/approximate the total energy of a single molecule in a cluster of few molecules via Multiwfn (contribution of a single molecule into the total energy of the cluster which we calculate via QM) ? (something like calculating per atom energies via energy decomposition analysis but instead of atom, this time for a whole molecule).
thanks in advance for any help.
Best regards,
A.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,777

Website

Re: Evaluate contribution of energy from a single molecule

Hello,

In principle it is possible, you simply need to sum up atomic contributions as molecule contribution.

amin.alibakhshi@hotmail.c

Member

Registered: 2019-08-25

Posts: 23

Re: Evaluate contribution of energy from a single molecule

Hello,

In principle it is possible, you simply need to sum up atomic contributions as molecule contribution.

many thanks prof. Lu both for your answer and for your super great job
one last question, is it already implemented and can be carried in Multiwfn? If yes, I would appreciate some few hints
Best regards,
Amin

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,777

Website

Re: Evaluate contribution of energy from a single molecule

You can use basin analysis module to integrate energy density in atomic basin to derive atomic contribution to system energy, then you need to manually sum up atomic contributions to fragment contribution. You also need to revise the integration value according to virial ratio if DFT is used.

I intend to add corresponding example in Section 4.17 of Multiwfn manual, however currently I am in terrible busy. I plan to upload updated Multiwfn manual after 5~6 days, and meantime will let you know here.

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,777

Website

Re: Evaluate contribution of energy from a single molecule

I have updated Multiwfn manual and upload it to Multiwfn website, the newly added Section 4.17.9 illustrated how to derive atomic energy using basin analysis module.

amin.alibakhshi@hotmail.c

Member

Registered: 2019-08-25

Posts: 23

Re: Evaluate contribution of energy from a single molecule

thanks so much