def calc_conductivity_cm2(conductance, capacitance):
    """Conductivity (S/cm²) of a membrane.

    The return value can be used directly by most NEURON mechanisms.

    Parameters
    ----------
    conductance : float
        Conductance of the membrane in siemens (S).
    capacitance : float
        Capacitance of the membrane in farad (F).

    Returns
    -------
    float
        Conductivity in S/cm² that can be consumed by most NEURON
        mechanisms.

    """
    cm = 9e-07
    area = capacitance / cm
    conductivity = conductance / area
    return conductivity
