# Question on aiida-vibroscopy utils/spectra.py

**URL:** <https://aiida.discourse.group/t/question-on-aiida-vibroscopy-utils-spectra-py/382>\
**Category:** General Usage\
**Created:** [May 9, 2024, 8:54pm UTC](https://aiida.discourse.group/t/question-on-aiida-vibroscopy-utils-spectra-py/382 "2024-05-09T20:54:49Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![rkarkee](https://avatars.discourse-cdn.com/v4/letter/r/a88e4f/32.png) [@rkarkee](https://aiida.discourse.group/u/rkarkee)\
**Post date:** [May 9, 2024, 8:54pm UTC](https://aiida.discourse.group/t/question-on-aiida-vibroscopy-utils-spectra-py/382/1 "2024-05-09T20:54:49Z")

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Hi @bastonero

In the utils/spectra.py while calculating prefactor: as you stated in comment and paper (for Stokes), I am seeing you missed to add 1 in the return statement. Can you please confirm it if current is right or you may need to do following: (unless adding 1 is insignificant).

return pre \*( boson\_factor(frequency, temperature)+1) \* (laser - frequency)\*\*4 / frequency

```auto
def raman_prefactor(frequency: float, frequency_laser: float, temperature: float, absolute: bool = True) -> float:
    r"""Return the Raman prefactor.

    :param frequency: frequency in cm^-1
    :param frequency_laser: frequency in nm (nanometer)
    :param temperature: temperature in Kelvin
    :param absolute: whether to use the conversion factor for theoretical Raman cross-section,
        which gives the intensities in (sterad^-1 cm^-2), default to True
    :return: the scalar :math:`(\\omega_L-\\omega)^4 [n(\\omega,T)+1] / \\omega`
    """
    from aiida_vibroscopy.common.constants import DEFAULT

    pre = DEFAULT.raman_xsection if absolute else 1
    laser = nanometer_to_cm(frequency_laser)

    return pre * boson_factor(frequency, temperature) * (laser - frequency)**4 / frequency

```

Best  
Rijan

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**Author:** ![bastonero](https://yyz2.discourse-cdn.com/free1/user_avatar/aiida.discourse.group/bastonero/32/32_2.png) [@bastonero](https://aiida.discourse.group/u/bastonero)\
**Post date:** [May 12, 2024, 9:17pm UTC](https://aiida.discourse.group/t/question-on-aiida-vibroscopy-utils-spectra-py/382/2 "2024-05-12T21:17:32Z")

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Hi, as stated in the docstring of `boson_factor`, that returns `(n+1)`.

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/aiida/original/1X/c417197d3750949351575d03ed03f5e2ad32e649.png) [@system](https://aiida.discourse.group/u/system)\
**Post date:** [May 12, 2026, 9:18pm UTC](https://aiida.discourse.group/t/question-on-aiida-vibroscopy-utils-spectra-py/382/3 "2026-05-12T21:18:23Z")

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Closed on May 12, 2026, 9:18pm UTC

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