Δa is a parameter for limiting each update. To gradually update the molecular species, Δa was set to 0.01 at each design step. λ is obtained by a bisection search to satisfy constraint Eq. ( ). The effectiveness of the algorithm comes from the fact that each ai is updated independently of the others, except for the scaling that must take place to satisfy Eq. (2). To obtain the candidate molecular species ( ) as the numerical procedure, optimized a are rounded off and converted into integers. From Eq. ( ), it is found that the candidate molecules are stationary points. Therefore, the candidate molecule can be obtained by MDM. When starting the exploration from the candidate molecule, a must be varied slightly.