| Computational chemistry is a quickly developing field. It is extensively utilized to overcome complex synthetic and biochemical difficulties in the pharmaceutical industry and academia. Considering the accuracy, the cost, and the time of computation for the methods used, Density Functional Theory (DFT) is more accurate than semiempirical methods. However, the computer time and cost savings of using semiempirical methods can be very beneficial, especially when macromolecules are being investigated. Thus, we are trying to examine the accuracy of fast available techniques using the RM1 semi-empirical molecular orbital method to calculate the properties of selected bioisosteres. Thus, the RMI method was used to correlate experimental data and DFT values with those predicted by RMI. We wanted to detect if the method can present strong relationships and predictions of DFT values. The readily available software packages, Avogadro and MOPAC (Molecular Orbital PACkage), were used to generate results that are compared to results obtained previously by us (Lisa Johnson's MS Thesis) using DFT (6-31G*/EDF2). The good correlations with DFT (6-31G*/EDF2) have been achieved for the dipole moment, ionization potential, the electron affinity, HOMO energy, electronegativty and hardness. Poor correlations with DFT (6-31G*/EDF2) were found for LUMO energy and gap energy. Thus, RM1 results can be accurately scaled for the dipole moments, ionization potentials, the electron affinity, HOMO energy, electronegativity and hardness, but it cannot be accurately scaled for the LUMO energy or gap energy for such molecules. |
