def F0F2F4_to_UJ(F0, F2, F4):
    """
    Given :math:`F_0`, :math:`F_2` and :math:`F_4`, return :math:`U` and :math:`J`. 

    Parameters
    ----------
    F0 : float
        Slater integral :math:`F_0`.

    F2 : float
        Slater integral :math:`F_2`.

    F4 : float
        Slater integral :math:`F_4`.

    Returns
    -------
    U : float
        Coulomb interaction :math:`U`.
    
    J : float
        Hund's coupling :math:`J`.
    """

    U=F0 + 4.0/49.0*(F2+F4)
    J=3.0/49.0*F2+20/441.0*F4

    return U,J