“…The Na, V(1), V(2), V(3), O(1), O(2), and O(3) atoms are located at the Wyckoff sites 2c (1/3, 2/3, 1/4), 6g (1/2, 0, 0), 4e (0, 0, z), 2d (1/3, 2/3, 3/4), 12k (x, 2x, z), 6h (x, 2x, 3/4), and 4f (1/3, 2/3, z), respectively. The details of our structural refinement are presented in tables 1 and 2 5 .…”