def print_settings(settings):
    """
    This function returns the harmonic approximation settings .

    Returns
    -------

    text: str
        Pretty-printed settings for the current Quantas run.

    """
    text = '\nCalculator: Harmonic Approximation\n'

    text += '\nTemperature settings\n'
    text += '-------------------------------------\n'
    text += ' - {:5} {: 8.2f} {}\n'.format(
        'min:', settings['trange'][0], settings['temperature_unit'])
    text += ' - {:5} {: 8.2f} {}\n'.format(
        'max:', settings['trange'][1], settings['temperature_unit'])
    text += ' - {:5} {: 8.2f} {}\n'.format(
        'step:', settings['trange'][2], settings['temperature_unit'])

    text += '\nMeasurement units\n'
    text += '-------------------------------------\n'
    text += ' - {:12} {}\n'.format('energy:', settings['energy_unit'])
    text += ' - {:12} {}\n'.format('lenght:', settings['lenght_unit'])
    text += ' - {:12} {}\n'.format('frequency:', settings['frequency_unit'])
    text += ' - {:12} {}\n'.format('temperature:', settings['temperature_unit'])
    return text