Draw HOMO LUMO with psikit #RDKit #Psi4 #PyMol

Now I and @fmkz___ are developing a thin wrapper library for Psi4 and RDKit named psikit.
Today I added new function for viewing molecular orbital HOMO and LUMO with pymol. Psi4 has the function which can output cube format file of MO named ‘cubeprop’. So I try to implement the function in to psikit.
By using the library, you can get HOMO/LUMO cube file easily.
Example is below.

from rdkit import Chem
from rdkit.Chem import Draw
from rdkit.Chem import AllChem
from rdkit.Chem.Draw import IPythonConsole
from psikit import Psikit
smi = 'COc1cccnc1'
mol = Chem.MolFromSmiles(smi)

Just call ‘getMOview’ after optimization. It took a little bit long time on my PC.

pk = Psikit()
%time pk.optimize()
>Optimizer: Optimization complete!
>CPU times: user 1min 54s, sys: 3.97 s, total: 1min 58s
>Wall time: 31.5 s
# get MO view!

After executing the method, psikit makes 5 files named target.mol, Psi_a_n_n-A.cube, Psi_b_n_n-A.cube, Psi_a_n+1_n+1-A.cube, Psi_b_n+1_n+1-A.cube. First file is mol file. Second and third is information of its HOMO and forth, fifth is information of LUMO.

Then load all files from pymol. Change HOMO/LUMO object show setting as dot. I could get following image.

Optimized molecule
Molecule and HOMO
Molecule and LUMO
Molecule and HOMO/LUMO

The function and pymol seem to work fine. But I want to compare data between this result and another QM’s result.
Current version of psikit is still under development and some bugs. I would like to fix and tune the code.


Published by iwatobipen

I'm medicinal chemist in mid size of pharmaceutical company. I love chemoinfo, cording, organic synthesis, my family.

4 thoughts on “Draw HOMO LUMO with psikit #RDKit #Psi4 #PyMol

  1. I love your blog!! I have a question about psikit. Is it possible (or are you planning) to calculate the RESP charges and embed them to pdb or mol2 file format? I think it would be interesting for people in the MD field, since RESP charges are usually calculated using Gaussian or GAMESS.

    1. Thank you for your comment. I do not think about it, but current version has resp_charge method as a property.
      The method calculate RESP charge of given molecule and return the result as a rdkit mol object with RESP charge which is embedded in atom feature. If you want to mol2 file, you can get by using rdkit.Chem.rdmolfiles.MolFromMol2File method.
      I hope this will be answer for your question.

      1. Thank you for your reply. Psikit utility looks very useful. I’ll give it a try to embed the RESP charges using Psikit and RDKit and compare it with well known QM packages.

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