Constructing transformation paths for conformational changes in (MgF₂)_n clusters using a stochastic procedure

Abstract

We present a stochastic optimisation procedure using simulated annealing for studying conformational changes in $({\mathrm{MgF}}_2{)}_n$ clusters. The pathways for transformation between stable geometries through a transition state is studied for cluster sizes n=3−12. The work uses an objective function which exploits the sign of the eigenvalues of the Hessian matrix to locate transition states. Once it is located for a specific size it is examined if one minimum geometry can be converted to another through the transition state. The potential energy surface for the system is searched using the stochastic optimisation procedure of simulated annealing. The ruggedness of the surface makes the choice of the optimiser an ideal one. To complete the results the progress of the pathway is depicted as the function of the path coordinates at intermediate geometries.

GRAPHICAL ABSTRACT

Keywords:

• Simulated annealing
• molecular cluster
• reaction path
• transition states

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

P.N. sincerely acknowledges Council of Scientific & Industrial Research: Human Resource Development Group, New Delhi, India for the award of a Senior Research Fellowship [File No: 09/028(0938)/2014-EMR-I].