generated by phonopy
   1.0
     0.0000000000000000    2.8458469972855682    2.8458469972855682
     2.8458469972855682    0.0000000000000000    2.8458469972855682
     2.8458469972855682    2.8458469972855682    0.0000000000000000
Na Cl
   1    1
Direct
  0.0000000000000000  0.0000000000000000  0.0000000000000000
  0.5000000000000000  0.5000000000000000  0.5000000000000000
