Paper ID: 2208.09273

Atomistic structure search using local surrogate mode

Nikolaj Rønne, Mads-Peter V. Christiansen, Andreas Møller Slavensky, Zeyuan Tang, Florian Brix, Mikkel Elkjær Pedersen, Malthe Kjær Bisbo, Bjørk Hammer

We describe a local surrogate model for use in conjunction with global structure search methods. The model follows the Gaussian approximation potential (GAP) formalism and is based on a the smooth overlap of atomic positions descriptor with sparsification in terms of a reduced number of local environments using mini-batch $k$-means. The model is implemented in the Atomistic Global Optimization X framework and used as a partial replacement of the local relaxations in basin hopping structure search. The approach is shown to be robust for a wide range of atomistic system including molecules, nano-particles, surface supported clusters and surface thin films. The benefits in a structure search context of a local surrogate model are demonstrated. This includes the ability to transfer learning from smaller systems as well as the possibility to perform concurrent multi-stoichiometry searches.

Submitted: Aug 19, 2022