Raman Spectra Specific orientation

Questions
#1

Dear all,

Briefly, im trying to calculate raman spectra of molecules that are fixed within a material. The qchem output gives only the activity and depolarization ratio, but i am interested, for example in the spectrum obtained when shining x-polarized light on the molecule and measuring the y-polarized raman scattering spectrum.

I did a lot of digging and what I found is that the raman polarizability tensor is typically calculated, by calculating the polarizability at displaced geometries, projected onto the normal modes, to give a raman polarizability tensor per normal mode. From this:

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The mean polarizability and polarizability anisotropy can be calculated, and the final Raman activity, orientation average is calculated from these. What I would need is the raw Raman polarizability tensor per normal mode. - Would this be possible to get using Qchem?

#2

So what you want are the polarizability derivatives, d(alpha_ij)/dx where x = 1,…,3N is a nuclear cartesian, which you could then transform into derivatives w.r.t. normal modes. Correct? The full set of polarizability derivatives are calculated whenever DORAMAN=TRUE (Raman vib intensity calculation), but they are not printed out. Would be easy to do if you have source code (developer) access.

#3

Yes indeed! Would it be possible for me to get this?

#4

If you have a valid Q-Chem license you can obtain source code access by signing a non-disclosure agreement. Please contact Q-Chem support.

When you are ready to do this, send me an email and I can show you the appropriate changes, seems straightforward based on a quick look at the code.