The initial processing of the gas electron diffraction data: An improved method for obtaining intensity curves from diffraction patterns

The present maximum precision of the geometric parameters of molecules obtained by gas-phase electron diffraction method (GED) is about 0.1%. The most important factors that control the accuracy of GED structural analysis are the accuracy of electron wave length estimation and measuring of the intensity curves. In this article an improved algorithm and a program for estimating the center of gas-phase electron diffraction patterns, sector center, intensity curve, and additive asymmetric background are presented. The application of proposed method of the initial processing of electron diffraction patterns to benzene molecule leads to least squares error of about 0.01% in ra(C–C) distance. The suggested algorithm can be used with primary data obtained both with scanner and the Image Plates technique. The dependence of estimated parameters on scanning conditions (resolution and bit depth) was also investigated.