3.3 Properties of Solid Nitrogen

Many properties of solid (and liquid) nitrogen are reviewed very thoroughly in an article by T.A. Scott [20]; the most important characteristics are briefly reviewed here.

The isolated nitrogen molecule N₂ has dimensions, defined by the surface enclosing 95% of the electron density, of about 3.39 Å diameter $\times$ 4.34Å in length. Spectroscopic studies of the vibrational (stretch) modes of the molecule indicate that in the condensed states the molecule is slightly distorted by interactions with neighbouring molecules.

Nitrogen exists as two stable isotopes - 99.63% is ¹⁴N with nuclear spin 1 and 0.37% is ¹⁵N with spin 1/2. With such a small fraction of ¹⁵N₂ the properties of solid, natural N₂ and solid pure ¹⁴N₂ are virtually indistinguishable.