None radius for He Ne

[LanceKnight]

Hello, I'm a new user of pymatgen. When I try to calculate the radius of He and Ne, I got None. I guess this is designed so on purpose. Can someone explain to me why?

[CompRhys]

This is just that there is no provided radius in the data source, https://github.com/materialsproject/pymatgen/blob/master/pymatgen/core/periodic_table.json

e.g. for He

   "He":{
      "Atomic mass":4.002602,
      "Atomic no":2,
      "Atomic orbitals":{
         "1s":-0.570425
      },
      "Atomic radius":"no data",
      "Atomic radius calculated":0.31,
      "Boiling point":"4.22 K",
      "Brinell hardness":"no data MN m<sup>-2</sup>",

[LanceKnight]

Thanks!