Structure analyses combining electron diffraction and microwave data : I. Study of XeOF4

Abstract

Molecular parameters for XeOF4 derived from electron diffraction data are compared with those previously reported in vibrational and rotational spectroscopic studies of the molecule. Additional least-squares calculations were performed which simultaneously fitted the diffraction and microwave data. Although results for the separate experiments are in good agreement, each set of parameters suffers from fairly large uncertainties which are largely unrelated to the accuracy of the respective physical measurements. A comparison of parameter correlations for the separate and joint least-squares calculations indicates that the troublesome Correlations in the individual sets of data are significantly reduced when the two sets of data are combined. Various interpretational difficulties associated with the process of combining the data from the two experiments are discussed and suggestions are made for estimating uncertainties in cases where the observational residuals are far from random.