Abstract
In this study, the spectral and molecular parameters are calculated by some molecular programs to obtain of the results of our compounds. The various properties of the ground and excited electronic states of The pyrromethene 580 molecule was theoretically simulated in this study utilizing density functional theory (DFT) and the B3LYP at a 6-31 G (d,p) basis set. Then, bond lengths and bond angles were determined using DFT methods, The electronic properties such as the electronic energy, dipole moments, such as ionization potentials (IP), absolute softness (S), chemical potential (K), electrophilic index (ω), electron affinities (EA), absolute hardness (η), Molecular electrostatic potential (MEP) and Absorption spectra. The energy values were -1192.534269 Hartree. The dipole moment values found to be 3.96 Debye indicate the non-uniform distribution of charges. The energy gap was found to be 2.96 eV, which reflected the stability of the molecule. We find good agreement between experimental and theoretical data of UV spectrum where λ_max theoretically with solvent ethanol was 513 nm and experimentally was 519-522 dependent on the change in concentration.