Density Functional Theory (DFT) plays a vital role in the study of organic materials. Lawsonia inermis is identified among the promising organic candidates to replace toxic and expensive solar cell material. The present study reported step by step computational procedure used to exposed the beauty of the organic solar cell candidate using Gaussian09 software. Stability check, optimization at different basis set, Homo-Lumo, band gap and Infrared spectrum (IR) at different medium were reported. It was found that the ground state energy, Homo-Lumo at both vacuum and Medium, band gaps, were found to be -16607.3717574 eV, -7.431 eV -3.584 eV (Vacuum) -7.311 eV -3.515 eV (Medium) 3.847 eV (Vacuum) 3.79 eV (Medium) respectively. For the IR it was found that there is shift and increase in the intensity due to the solvent effect on the material. These results were compared with the literature and are in agreement. It can be concluded that the Lawsonia inermis at solvent medium can enhance smooth and easier electron hole transport by looking at the band gap and hence it can and will be a good candidate organic material for solar cell production.