The structure and properties of niobapyrimidinium complex were examined by density functionaltheory method (mpw1pw91). The effect of solvent on the structural parameters, frontier orbitalenergies and hyperpolarizability (
tot) of this molecule has been explored. The thermodynamicproperties of the title compound at different temperatures have been calculated. Also, the parasubstitutionseffect on the structure, frontier orbital energies, aromaticity and hyperpolarizability (
tot)has been studied. Nucleus independent chemical shift (NICS) values show that these species arearomatic.