Everyone knows simple classical model of dielectric susceptibility called Lorentz oscillator model, in other words, spring mass model. But I can't find it's all parameter values for different atoms: resonance (spontaneous) frequency - ω0 = \sqrt{k/m}, 2) effective mass of electron - m, 3) damping coefficient - γ = 1/τ, τ - relaxation/scattering time. If there are experimenters or specialists from relating fields which have knowledge of handbooks, databases, catalogs or any writings for experementers, of values of ω0, m, γ, plasma frequency ωp, real (refractive index or relative permittivity) and imaginary parts of susceptibilities \chi(1), please provide information on them.
Related question is the following: Has the Lorentz model expanded for diatomic, triatomic, ... multiatomic molecules? Is it useful for theoretical description of susceptibilities for multiatomic molecules? Why yes or why not? Please provide relevant information.
Thank you in advance...
Dear Hayk L. Gevorgyan , please have a look into this book: https://www.sciencedirect.com/book/9780125444224/handbook-of-optical-constants-of-solids - it should answer all your questions.
Dear Thomas Mayerhöfer thank you for your reply. Interesting book and sure it can answer to many questions and is very useful. Frankly speaking, I extended the Lorentz model for diatomic and multiatomic molecules. I would like to know if my modified consideration can be valuable for diatomic or multiatomic molecules and has physical meaning for at least some of them. For that I will need the parameters mentioned in my question which I didn't find in your mentioned handbook. The model resulting in the formulas for susceptibility and resonance frequency of diatomic or multiatomic molecules which depend on the mentioned parameters for individual atoms and other unknown parameters for now (of my knowledge this consideration has not yet been done).
Hayk L. Gevorgyan I see. I guess the question is what features in spectra did you have in mind that cannot be modeled with the conventional model.
E.g., in the infrared spectral range the damped harmonic oscillator model (or Lorentz-model) works quite well for any molecular substance. For more ionic materials with very large oscillator strengths like BaTiO3, there are several different 4-parameter models, which are useful, e.g., in particular for coupling effects. Other further developments of dispersion theory consider vibrational circular dichroism, non-linear effects due to very intense light sources etc. Also, there are more sophisticated models to model semiconductor band gaps, anisotropic materials etc. If you tell me which particular effect in spectra your model is suitable for, I may be able to point you to the corresponding literature.