Perturbation theory based model can be used to locate the quasi-degeneracy in an arbitrary double well potential. In this work, unconstrained optimisation has been done using Simulated Annealing to calculate the energy spectrum of double well potential. Using this calculation the author has studied the effect of a Gaussian perturbation on single and double well potential. A comparative study of quartic double well potential and Gaussian double well potential has also been done on the basis of chemical and statistical point of view. The efficiency of this method is notable. Numerical calculation shows that the proposed method can give extremely accurate results for symmetric double well potentials.