Global geometry optimization of (Ar)n and B(Ar)n clusters using a modified genetic algorithm

Abstract
A modified deterministic/stochastic genetic algorithm (DS‐GA) method is proposed for the determination of the global minimum of atomic clusters described by pairwise analytic interaction potentials. Our modification of the standard GA method involves a coarse local minimization of each member of the population at every generation, as well as including the gradient into the fitness function. For Lennard‐Jones (Ar)n clusters with n2P) with multiple Ar atoms. The interaction potential is given by the lowest state of a 3×3 electronic Hamiltonian. The Ar–Ar potential and the lower energy (Π state) B–Ar potential are very similar. In contrast, the higher energy (Σ state) B–Ar interaction is essentially repulsive. Consequently, the B atom is nearly always found to substitute for one of the atoms in the corresponding (Ar)n+1 cluster with the fewest number of nearest neighbors.