lineshape_tools.lineshape¶

Implements functionality to evaluate optical lineshapes.

Functions¶

`get_Stot`(→ float)	Calculate the Huang-Rhys factor Stot.
`gaussian`(→ numpy.ndarray)	Evaluate the Gaussian function with smearing s.
`lorentzian`(→ numpy.ndarray)	Evaluate the Lorentzian function with broadening g.
`get_phonon_spec_func`(→ tuple[numpy.ndarray, ...)	Compute the phonon spectral function and related quantities.
`convert_A_to_L`(→ tuple[numpy.ndarray, numpy.ndarray])	Convert phonon spectral function into a (normalized) optical intensity.

Module Contents¶

lineshape_tools.lineshape.get_Stot(dq: numpy.ndarray, omega: numpy.ndarray) → float[source]¶

Calculate the Huang-Rhys factor Stot.

Parameters:

dq (np.ndarray) – mass-weighted displacement vector in normal mode basis in (amu^{1/2} Ang).
omega (np.ndarray) – normal mode phonon frequencies (in eV/amu/Ang^2).

lineshape_tools.lineshape.gaussian(x: numpy.ndarray, s: float) → numpy.ndarray[source]¶: Evaluate the Gaussian function with smearing s.

lineshape_tools.lineshape.lorentzian(x: numpy.ndarray, g: float) → numpy.ndarray[source]¶: Evaluate the Lorentzian function with broadening g.

lineshape_tools.lineshape.get_phonon_spec_func(

dq: numpy.ndarray,

omega: numpy.ndarray,

broadening: Broadening | None = None,

resolution: float = 0.001,

w_max: float | None = None,

pad: float = 0.1,

T: float = 0.0,

**kwargs,

) → tuple[numpy.ndarray, numpy.ndarray, numpy.ndarray, numpy.ndarray][source]¶

Compute the phonon spectral function and related quantities.

If broadening is not provided, kwargs will be passed to Broadening.create (see Broadening.create()).

When T == 0. (the default), an optimized evaluation of the spectral function is utilized.

Parameters:

dq (np.ndarray) – mass-weighted displacement vector in normal mode basis in (amu^{1/2} Ang).
omega (np.ndarray) – normal mode phonon frequencies (in eV/amu/Ang^2).
broadening (Broadening) – instance of Broadening.
resolution (float) – desired energy resolution (in eV) of the calculated spectral functions.
w_max (np.ndarray) – maximum frequency in grid.
pad (float) – energy (in eV) below ZPL to pad the spectral function.
T (float) – Temperature in kelvin.
**kwargs – keyword arguments passed to Broadening.create() when broadening is not provided as input.

Returns:

frequencies at which the functions were evaluated at (ħω) dos (np.ndarray): phonon density of states ρ(ħω) S_w (np.ndarray): Huang-Rhys spectral density S(ħω) A_w (np.ndarray): spectral function A(ħω)

Return type:

w (np.ndarray)

lineshape_tools.lineshape.convert_A_to_L( w: numpy.ndarray, A: numpy.ndarray, dE: float, emission: bool = True, norm: str = 'area', ) → tuple[numpy.ndarray, numpy.ndarray][source]¶

Convert phonon spectral function into a (normalized) optical intensity.

Parameters:

w (np.ndarray) – frequencies (in eV) where A is evaluated.
A (np.ndarray) – spectral function.
dE (float) – energy of the zero-phonon line.
emission (bool) – determines if the intensity corresponds to emission or absorption.
norm (str) – normalization of luminescence (area or max).

Returns:

expanded range of frequencies where intensity is evaluated. L (np.ndarray): optical intensity L(ħω) on expanded frequencies new_w.

Return type:

new_w (np.ndarray)