rotational_partition

def rotation_partition_function(moment_of_inertia: float,
    temperature: float) -> float:
    """
    Calculates the rotational partition
    function for linear molecules.

    >>> round(rotation_partition_function(1e-46, 300), 4)
    5.9275
    >>> round(rotation_partition_function(2e-46, 300), 4)
    11.855
    >>> round(rotation_partition_function(-2e-46, 300), 4)
    Traceback (most recent call last):
        ...
    ValueError: Moment of inertia must be positive
    >>> round(rotation_partition_function(1e-46, -300), 4)
    Traceback (most recent call last):
        ...
    ValueError: Temperature must be positive
    """

    if moment_of_inertia <= 0:
        raise ValueError("Moment of inertia must be positive")
    if temperature <= 0:
        raise ValueError("Temperature must be positive")

    k_B = 1.380649e-23  # Boltzmann constant
    h = 6.62607015e-34  # Planck's constant

    return (2 * math.pi * moment_of_inertia * k_B * temperature) / (h ** 2)

if __name__ == "__main__":
    import doctest
    doctest.testmod(name="rotation_partition_function")