Transmission electron diffraction studies were carried out on N2O film
s grown at temperatures 11-18 K and subsequently slowly warmed up to 4
5 K. The structure data obtained made it possible to identify the repo
rted earlier [1] abrupt changes of the reflectivity bands at the intra
molecular frequencies of N2O above 40 K as a crystallization transform
ation in which the amorphous component (whose very existence is an ano
maly, characteristic only of N2O among all the cryocrystals [2]) loose
s its stability and undergoes a fast crystallization forming the Pa3 s
tructure.