references:
- J.A. Rayne and B.S. Chandrasekhar,
Physical Review 120(5):1658-1663, 1960,
https://doi.org/10.1103/PhysRev.120.1658
- https://en.wikipedia.org/wiki/Tin
lattice: tI
c/a: 0.5458 # T=300K (c=31.83nm, a=5.832nm)
rho: 7265.0