Abstract: | Intermolecular interactions in solid ammonia are investigated in a combined X-ray spectral and quantum chemical study. Theoretical
NKα spectra are constructed on the basis of MNDO calculations of the ammonia molecule and (NH3)7 and (NH3)13 clusters modeling solid ammonia; the spectra are in satisfactory agreement with the experimental X-ray spectra. Fragment
analysis of the clusters with respect to the central ammonia molecule is carried out. It is shown that intermolecular electronic
interactions in solid ammonia are most effective in MOs of e symmetry (σ-binding of nitrogen and hydrogen atoms). The fragment
2a1 orbital contributes to the MO structure of the clusters to the least extent.
Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 4, pp. 721–726, July–August, 1996.
Translated by L. Smolina |