Geometric modeling and geometric optimization of Fe(III)-1,10-phenantroline (Fe-Phen), Ni II)-1,10-phenantroline (Ni-Phen) and Zn(II)-1,10-phenantroline (Zn-Phen) compounds have been carried out computing using the semi-empirical method of PM3. The spectral measurements and the study of complex electronic compositions using the UV-Vis spectrophotometer and simulation of ZINDO/s (Zerner's Neglect of Differential Overlap) calculations. The optimum result of the geometry of complex molecule found there is a change of charge in each complex with stable energy. The UV-Vis spectra measurements showed λmax in the Fe-Phen complex: 315.50 nm, Ni-Phen complex: 325.00 nm and Zn-Phen complex: 315.00 nm. The electronic transition occurring at these three complexes shows the transition characteristics of electrons at the level of the molecular orbitals π to π* and the degree of the molecular orbitals n to π⃰. Electron transition energy in complex orbital molecules can be observed in the energy changes of each molecular orbitals.