• LUMO field;
  • CoMFA;
  • semi-empirical methods;
  • TA100 mutagenicity;
  • MX compounds


In the present paper we make a comparison among three different semi-empirical methods (AMI, MNDO and PM3) for the optimization of the geometries and calculation of different properties of MX compounds. The results were used to develop a CoMFA model to correlate the TA100 mutagenicity of these compounds with the LUMO field. The correlations between the LUMO field and steric, electrostatic and CoMFA fields generated automatically by the SYBYL CoMFA program, were explored. A comparison among different values of grid spacing for the lattice and standard deviation thresholds for column filtering was carried out to select the best values for this and future work.

The results indicate that AM1 and PM3 methods represent a real improvement over MNDO in respect to QSAR studies relating electronic properties and mutagenicity for these compounds.