Multiwfn forum

Hello,

I’m wondering if we could calculate ESP fitting charge using density cube file.

I understood that ESP charges by such as CHELPG and MK were easily calculated using wfn or fchk files.
But I couldn’t find the way to do the same thing using only density cube file.

Thanks in advance for you help!

Hi.

I have a question about fuzzy bond order (FBO) analysis.
The command I used is as follows: run Multiwfn a.wfn (excited state density), then input 9 (BOA), then input 7 (FBO).
Then I received a message “Note: Some occupation numbers are negative. “
In this case, what is the occupation number? Bond order?

This didn’t occur for ground state analysis, but excited one.
Thinking about the possibility of the density being wrong, let me describe how I obtained the excited state density.
I ran Gaussian job with option “td=(nstates=1,root=1) density=current our=wfn”
The wfn file I mentioned above was obtained this way.
Furthermore, by using fchk made from this job’s chk file, I obtained Molden file for relaxed excited state density (I ran Multiwfn a.fchk, input 200, input 16, input CI, and input y) and tried FBO analysis using this Molden file, but the same issue occurred.

Hello.

Is there any “good way” for bond order analysis (BOA) of excited states?
Let me elaborate on the current situation below.

I’m interested in how bond orders change in the excited state from the ground state.
(I’ve tried excited state analysis such as q_CT and density difference already, and now want deeper insight into bonds.)

The problem is that I don’t see many papers related to this subject.
After reading the chapter 3 in the Multiwfn manual,
I recognized that some BOA methods should not be applied to excited state analysis, which requires diffuse functions in basis sets to accurately describe the electron density.
Therefore, in my opinion, fuzzy bond order analysis or laplacian bond order analysis, which don’t heavily depend on basis sets, are good choice.

Is there any comment or any better choice on excited state BOA?
Thanks in advance.

Hi,

I’d like to ask how to make a histogram using density difference on a molecular surface.
(Density difference between ground and excited states)

What I want to do is similar to the description in “quantitative analysis of molecular surface” in the manual.
There, I found a histogram with horizontal axis representing ESP and vertical axis representing surface area.
I’m trying to make a histogram with horizontal axis representing density difference and vertical axis representing surface area, instead.

My current situation is that I successfully made density difference cube file by cubman, “su” operation.
(I visualized this cube file on gaussview and confirmed the file was properly created)
So far, I obtained ground state density cube, excited state density cube, and density difference between them.
However, I don’t know how to proceed further.

Could anyone help? Thanks in advance.