Comparison of semi-empirical calculation methods

This article discusses semi-empirical calculation methods: PM3, PM6, AM1. The advantages and disadvantages of these methods are considered. The AM1 offers speed and versatility, but sacrifices some accuracy, while the PS3 improves accuracy while maintaining computational efficiency. PM6 further improves accuracy, especially for transition metal systems and biochemical systems. The choice of method depends on the objectives of the study, the size of the system and the desired accuracy. For comparison, the results of the calculation of the 2-nitrodiphenylamine molecule are presented. Calculations of optimization of geometry, binding energy, band gap width, IR spectrum, calculation time are performed.