Fit Function: EDE_b3Su

Fit Function \[\sigma (x) = A_1 \left( x - 1\right)^{-A_2^2} \exp\left[-\frac{A_3}{(x-1)^{A_4}} \right]\]
Comments Python code requires NumPy imported as `np`.

Python

Arguments
namedescriptionunitstype(s)
x energy in threshold units float, np.ndarray
A1 fit coefficient float
A2 fit coefficient float
A3 fit coefficient float
A4 fit coefficient float
Return values
namedescriptionunitstype(s)
sigma cross section a02 float, np.ndarray
Code 
def EDE_b3Su(x, A1, A2, A3, A4):
    """
    This function calculates the dissociative excitation cross sections (in a.u.) 
    of H2 isotopologues from the ground electronic state X to b(3SIGMA+u) state.

    param x: requested electron-impact energy in threshold units
    type x: float, np.ndarray
    param Ai: fit coefficients
    type Ai: float
    """
    sigma = A1* np.power((x-1),-A2**2) * np.exp(-A3/(x-1)**A4) 
    return sigma