dist_deriv

dist_deriv(coords, i, j): 

Gives the derivative of the distance between i and j with respect to coords i and coords j

coords: np.ndarray

No description…
i: int | Iterable[int]

index of one of the atoms
j: int | Iterable[int]

index of the other atom
:returns: np.ndarray

derivatives of the distance with respect to atoms i, j, and k