def METHOD_NAME(self, atom2):
    """ Get distance vector from one atom3D class to another.
    Parameters
    ----------
        atom2 : atom3D
            atom3D class of the atom to measure distance from.
    Returns
    -------
        dist_list : list
            List of distances in vector form: [dx, dy, dz] with units of Angstroms.
    """
    xyz = self.coords()
    point = atom2.coords()
    dx = xyz[0]-point[0]
    dy = xyz[1]-point[1]
    dz = xyz[2]-point[2]
    return [dx, dy, dz]