INDO calculations on the [Be3O(HCO2)3]+ ion configuration

SCF–MO–LCAO–INDO calculations show that the total energy of the Be₃O(HCO₂)₃]⁺ ion, which is the base peak in the mass spectra of the beryllium μ₄-oxoformato complex, depends on the deviation of the ion configuration from planarity. The planar form is shown to have the lowest energy. The results obtained confirm the suggestion that steric interactions are the major factor governing fragmentations of beryllium μ₄-oxocarboxylato complexes under electron impact.