Fit parameters

These parameters control the fit of the spectrum by a sum of normalised (unit area) Lorentzian resonances, used to extract transition frequencies and oscillator strengths. The spectrum is approximated as:

$$spectrum(\omega) = B+\sum_{k=1}^{N_{\hbox{\scriptsize trans}... ...psilon}{\pi}\frac{A_k}{ (\omega -\omega^0_k)^2 + \epsilon^2 }$$ (3)

where $N_{\hbox{\scriptsize trans} }$ is the number of Lorentzians, $B$ a constant to capture the background due to resonances outside the computed interval, $\omega^0_k$ the $k^{th}$ transition energy and $f_k = \frac{2}{\pi}A_k \omega_k^0$ its oscillator strength (see paper 3).

fit_lorentzian_sort

(integer): Specifies whether to sort transitions in order of energy (=1) or oscillator strength (=2).

Default: 2

fit_lorentzian_nbpoints

(integer): Controls whether a model spectrum (eqn. 3) is output. fit_lorentzian_nbpoints $> 1$ specifies the number of points output to file input_outputFileName_modelledSpectrum.txt. No output if fit_lorentzian_nbpoints $\leq 1$ . Default: -1