def overlap1d(l1,l2,PAx,PBx,gamma):
    """
    The one-dimensional component of the overlap integral. Taken from THO eq. 2.12
    >>> isclose(overlap1d(0,0,0,0,1),1.0)
    True
    """
    total = 0
    for i in range(1+int(floor(0.5*(l1+l2)))):
        total += binomial_prefactor(2*i,l1,l2,PAx,PBx)* \
                 fact2(2*i-1)/pow(2*gamma,i)
    return total
def overlap1d ( l1 , l2 , PAx , PBx , gamma ) : total = 0 for i in range ( 1 + int ( floor ( 0.5 * ( l1 + l2 ) ) ) ) : total += binomial_prefactor ( 2 * i , l1 , l2 , PAx , PBx ) * fact2 ( 2 * i - 1 ) / pow ( 2 * gamma , i ) return total
The one-dimensional component of the overlap integral. Taken from THO eq. 2.12
    >>> isclose(overlap1d(0,0,0,0,1),1.0)
    True