An automatic program to form the d_SH geometry of a molecule was developed. The program was based on the random function, and various d_SH geometries of each of the two molecules C₆B₃H₃ and C₆O₃ were obtained from the program. Then the NBO energetic analysis and Morokuma SCF energy partition were performed, over the NBO and LFMO basis sets respectively, for each of these geometries, and these two energy partitions could provide any specific d_SH geometry with the different values of the vertical resonance energy (VRE). At the same time, the driving force and resistant force for distorted molecules, obtained from the two different energy partitions over the NBO and LFMO basis sets, were compared. As a result, it is clear that the energy analysis results not only depend on the basis set but also on the analysis method. Furthermore, the results obtained from the NBO basis set and the NBO energetic analysis seem to be unsound.

Key words: d_SH distortion, random function, natural bond orbital, localized fragment molecular orbital (LFMO), vertical resonance energy