def METHOD_NAME(xyzf):
    # setting properties
    xyz = mol3D()
    xyz.readfromxyz(xyzf)
    # getting idxs of interest
    midx = xyz.findMetal()[0]  # monometallic complexes
    # list of idx of the first-coord sphere
    fidx_list = xyz.getBondedAtoms(midx)
    fvalency_list = []
    for idx in fidx_list:
        valency = len(xyz.getBondedAtoms(idx)) - 1
        fvalency_list.append(valency)
    return fvalency_list