VALENCE FORCE-FIELD OF 3-METHYL-4-NITROPY RIDINE N-OXIDE (POM)

The Simplified Generalized Valence Force Field of the 3-methyl 4-nitro pyridine N-oxide molecule (POM) has been determined. In order to veri fy the transferability of the force field from the parent molecule 4-n itro pyridine N-oxide (NPO) to POM, the calculations have been made fi rst using the C-H distances determined by X-ray diffraction for NPO, a nd the final results correspond to the real geometry determined by neu tron diffraction. Moreover, it has been necessary to re-assign 5 of th e observed vibrational frequencies of POM.