“…We use the Gaussian Approximation Potential (GAP) (Bartok et al, 2010), essentially a kernel ridge regression method (Kung, 2014). This is just one of a class of recently popularized machine learning methods for creating nonparametric interatomic potentials, which has been shown to be very successful in tackling difficult materials modelling problems, ranging from investigating the structure of amorphous materials (carbon (Deringer et al, 2017(Deringer et al, , 2019, silicon (Bartók et al, 2018)), the mechanics of metals (tungsten (Szlachta et al, 2014), iron (Dragoni et al, 2018)) to molecular liquids such (water (Bartók et al, 2013a), methane (Veit et al, 2019). There are many alternatives, using other regression frameworks, such as artificial neural networks (Behler and Parrinello, 2007) and even linear regression (Shapeev, 2017;Drautz, 2019).…”