Multiwfn forum

julieborah66

Member

Registered: 2018-09-17

Posts: 32

Electrostatic potential

Sir, as I am a new user of the software, can you tell me if I will be able to calculate the RMSE in case I have calculated the ESP from point charges(CM5 charges) and the Quantum ESP for my molecule?
If it is possible, 1. How to calculate the Quantum ESP for my molecule?
2. If i have generated the .chg file for my molecule in case of CM5 charges, how can i calculate the ESP in a grid and compare or calculate the RMSE compared to the Quantum ESP?
What is the step wise procedure?

Last edited by julieborah66 (2018-09-17 09:47:38)

I_was_a_baby

Member

Registered: 2017-09-11

Posts: 29

Re: Electrostatic potential

Sir, as I am a new user of the software, can you tell me if I will be able to calculate the RMSE in case I have calculated the ESP from point charges(CM5 charges) and the Quantum ESP for my molecule?
If it is possible, 1. How to calculate the Quantum ESP for my molecule?
2. If i have generated the .chg file for my molecule in case of CM5 charges, how can i calculate the ESP in a grid and compare or calculate the RMSE compared to the Quantum ESP?
What is the step wise procedure?

Sir:

There are several ways to calculate the ESP of your molecule by using Multiwfn.
The first method is applied according to quantitative molecular surface analysis. You can read the section 3.15 and 4.12 of manual of Multiwfn to discover the details.
The second one is that you can call the cubegen module of Gaussian program package to generate the cube files of ESP. You can modify the cubegenpath in setting.ini to do that.

After modifying, start up the Multiwfn.
5
12
2
calculating......
2
Then the Gaussian type cube file of ESP will be exported. Combining with cube file of molecular density, you can obtain the plot of ESP. Other questions can be answered in my article(http://bbs.keinsci.com/thread-10070-1-1.html, in Chinese)

The third, based on the atomic charge, is another useful way to do that. The article(//www.umsyar.com/wfnbbs/viewtopic.php?id=68) can be referenced.

best wishes
wawa
2018-09-18

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 1,773

Website

Re: Electrostatic potential

Dear julieborah66,

The ESP fitting charges based on wavefunction (including MK, CHELPG and RESP) can be calculated via main function 18 of Multiwfn. There is an example of calculating CHELPG charges in Section 4.7.1 of Multiwfn manual.

I just updated Multiwfn on official website today (the 3.6(dev) updated on 2018-Sep-18), this version is able to measure ESP reproducibility of given atomic charges at MK or CHELPG type of ESP fitting points in terms of RMSE and RRMSE. Please check Section 4.7.2 of the latest version of manual for example.

Regards,

Tian Lu