Scipy Factorial2 change

[shivupa]

SciPy's factorial2 behavior changed in this commit scipy/scipy@5e91097
(It seems like factorial2(x<1) should have always returned zero, but it used to only do that if exact=True)

When factorial2 is called here with 0 then the factorial array now gets 0 instead of 1.

This causes the following issue with scipy 1.11.4

/usr/local/lib/python3.11/site-packages/iodata/overlap.py:277: RuntimeWarning: divide by zero encountered in scalar divide
  return np.sqrt((4.0 * alpha) ** sum(n) * (2.0 * alpha / np.pi) ** 1.5

[PaulWAyers]

This is addressed in pending pull requestion #301 . For now, the work-around is to use scipy version 1.10 or less.

[shivupa]

Yup sorry I missed that!

[FarnazH]

Thanks, @shivupa for raising an issue. I just merged PR #301, so the code should work with any version of scipy.

[shivupa]

Thanks!