wyckoffs:
- "a"
- "a"
- "a"
- "a"
- "b"
- "b"
- "b"
- "b"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
- "f"
