Ben Johnston's 22-tone 7-limit just scale

note # ratio step
0 1/1 28/27
1 28/27 36/35
2 16/15 25/24
3 10/9 36/35
4 8/7 49/48
5 7/6 36/35
6 6/5 25/24
7 5/4 36/35
8 9/7 49/48
9 21/16 36/35
10 27/20 25/24
11 45/32 36/35
12 81/56 28/27
13 3/2 28/27
14 14/9 36/35
15 8/5 25/24
16 5/3 36/35
17 12/7 49/48
18 7/4 36/35
19 9/5 25/24
20 15/8 36/35
21 27/14 28/27

10/9-------5/3-------5/4------15/8-------45/32
| |\ /|\ /|
| | \ / | \ / |
28/27-----14/9-------7/6-------7/4------21/16
`.\ /,' `.\ /,'
1/1-------3/2
,'/ \`. ,'/ \`.
8/7-/---\12/7-/---\-9/7------27/14-----81/56
| / \ | / \ | |
|/ \|/ \| |
16/15------8/5-------6/5-------9/5------27/20

Great symmetry, but is it even a periodicity block?