Software To read psi4 output particularly vibration analysis


#1

Is there any software able To read and draw infrared spectra from vibration analysis output ? Thanks


#2

There are programs that will let you create the spectrum manually. I use matplotlib for this, and others may have their own favorites.

I’m not aware of a program that will automatically convert a Psi4 output file into a spectrum, and if there is such a program, it can’t be very good. Psi reports the frequencies, symmetries, and coordinates of normal modes, but to even draw a harmonic IR spectra, you’d like to have the intensities of the various modes, which Psi currently cannot compute. Fixing this is very high on our to-do list, but not done yet.


#3

We do have intensities! But only for HF and only if your Psi4 is less than a month old. So practically speaking, @jmisiewicz was spot on.

One of these days, the the Avogadro2 fellow and I really will get coordinated and hook up psi’s vib output to a visualizer. In the meantime, all we can do is provide a nice data structure. https://github.com/psi4/psi4/blob/master/psi4/driver/qcdb/vib.py#L337-L367 is what’s in frequency analysis in the below snippet

e, wfn = psi4.frequencies('mp2/cc-pvdz', return_wfn=True)
vibdata = wfn.frequency_analysis

#4

Once Psi4 has intensities, WebMO will be able to generate a possible spectrum. Currently WebMO will display an IR spectrum from a Psi4 output, but with all 0 intensities. So the base foundation is there. Once intensities are available, getting WebMO to read them in for visualizing will be a high priority for me.


#5

I forgot about that, but even those intensities are only for RHF, not general HF.