The Clinamen package

Clinamen: Covariance-matrix-adaptation evolution strategy for Localized Impurities with unsupervised Machine learning Exploration of Non-elementary structures.

Clinamen is a Python package implementing the covariance-matrix-adaptaion evolution strategy (CMA-ES) [HansenOstermeier01] for finding low-energy configurations of localized defects. It additionally employs an unsupervised machine learning (ML) approach for exploiting the structures visited by the evolutionary algorithm (EA) in order to find additional low-energy minima.

The meaning of the word clinamen

Clinamen is the name that the Roman philosopher and poet Titus Lucretius Carus gave to the random deviations in the rectilinear motion of atoms, which, according to the Epicurean atomistic theory, are responsible for their collisions and aggregation into objects.

In the De Rerum Natura, Lucretius also presents a theory of natural selection based on the random generation, by the Earth, of creatures of any sort, among which only the most fit ones are able to survive and reproduce.

The importance of the random generation of individuals and of fitness-based selection in the doctrine of Lucretius, together with the fact that clinamen can be used as an acronym describing the main ingredients of the method implemented in this package, are the main reasons for the choice of this name.