This article is organized as follows. We discussed the theoretical motivations behind using QDO model as well as computational methodologies in section 2. Next, we analysed the fragmentation procedure carefully in section 3.1 followed by the performance of our method for S66X8 database in section 3.2. Then we discussed the performance of other exchange-correlation functionals other than PBE in section 3.3. Finally, we conclude the paper in section 4.