ESP Surfaces with Psi4

[sbembenek]

I’m interested in using Psi4 to generate ESP surfaces.

To do so, I include:

cubeprop(wfn) which does produce the cube files.

1. It this the correct procedure?
2. What program are people using for the visualization – VMD? or?

thanks,

Scott

[araz]

Hi Scott,

The cubeprop(wfn) command is correct but you also need to specify that you want the ESP. Add these two lines before the cubeprop line:

set cubeprop_tasks [‘esp’]
E, wfn = energy(‘scf’, return_wfn=True)

For the second question, I found that VMD works well enough. A quick tip, make sure to load both the density and esp cube files into VMD, then display the density as an isosurface and then map the esp onto it…

Hope this helps.
Araz

[sbembenek]

Hi Araz,

thanks very much for your help!

I’m still a bit confused.

Using water as an example:

memory 10240 mb

molecule mol {
0 1
O 0.00000000 0.00000000 0.00000000
H 0.00000000 -0.79069000 0.61221700
H -0.00000000 0.79069000 0.61221700

}


set scf_type df
set basis 6-31G(d)
set reference rks
set_num_threads(32)

e, wfn = energy('b3lyp', return_wfn=True)
cubeprop(wfn)
set cubeprop_tasks ['esp']

mol.print_out()
print_variables() 

In this way, I end up with 2 sets (A, B) of 19 Cube files for each MOs – yes?

Not clear how to generate a single ESP surface from these files via (e.g., VMD).

thanks,

Scott

[araz]

Hi Scott,

Move the “set cubeprop_tasks [‘esp’]” line before calling the “cubeprop(wfn)” function. There should be only two cube files generated, one for the density and one for the esp.

Take care,
Araz

[sbembenek]

thanks very much. Yes, that did result in the two files.

I’m curious what your preference is for viewing the ESP surface. I’m fiddling with VMD and although everything loads correctly, I’m not able to get anything but a single color for the surface. Have you had success viewing ESP surface in VMD such that you get a color scale, rather then a single colored surface?

Is Molden an option – I seen Psi4 can write molden density files; still need the potential file, of course.

thansk,

Scott

[araz]

Hi Scott,

In VMD, go to the Trajectory tab in Graphical Representations and set the Color Scale Data Range. You should then see the colours.

Araz