A global optimization perspective on molecular clusters

Abstract

Although there is a long history behind the idea of chemical structure, this is a key concept that continues to challenge chemists. Chemical structure is fundamental to understanding most of the properties of matter and its knowledge for complex systems requires the use of state-of-the-art techniques, either experimental or theoretical. From the theoretical view point, one needs to establish the interaction potential among the atoms or molecules of the system, which contains all the information regarding the energy landscape, and employ optimization algorithms to discover the relevant stationary points. In particular, global optimization methods are of major importance to search for the low-energy structures of molecular aggregates. We review the application of global optimization techniques to several molecular clusters; some new results are also reported. Emphasis is given to evolutionary algorithms and their application in the study of the microsolvation of alkali-metal and Ca ions with various types of solvents.This article is part of the themed issue 'Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces'.

Size‐guided multi‐seed heuristic method for geometry optimization of clusters: Application to benzene clusters

“…This study uses the heuristic method combined with the geometrical perturbations to improve geometries. However, other algorithms, such as evolutionary algorithm and basin‐hopping algorithm, are also used as strategies of geometrical improvements. It would be very interesting to apply SGMS‐HMGP to other systems, multicomponent Lennard‐Jones atomic clusters, water clusters, and off‐lattice protein models .…”

“…In the step 3, seeds are selected with the energy‐based criterion after the selection of parents in evolutionary algorithms . However, this is not efficient for systems where similar seeds are often selected.…”

vdW‐TSSCDS—An automated and global procedure for the computation of stationary points on intermolecular potential energy surfaces

“…Methods that rely on a fit which uses a grid of nonstationary points in a physically meaningful range of intermolecular coordinates also exist in an automatic fashion. Alternatively, other approaches make use of genetic or evolutionary algorithms in combination with a large variety of different methodologies allowing for the determination of minimum energy structures of molecular clusters . However, to the best of our knowledge, these approaches are restricted to the so‐called rigid monomer approximation in which both monomers are constrained to their equilibrium geometries …”

Aggregation enhancement of coronene molecules by seeding with alkali-metal ions

“…Accordingly, the basin-hopping approach 13 and methods based on genetic algorithms [14][15][16] are perhaps among the most applied to discover low-energy structures of microsolvation clusters. In our group, we have used our own evolutionary algorithm 16 (EA) to perform microsolvation studies involving several ions and solvent molecules 17 .…”