Compressing local atomic neighbourhood descriptors

Abstract Many atomic descriptors are currently limited by their unfavourable scaling with the number of chemical elements S e.g. length body-ordered descriptors, such as SOAP power spectrum (3-body) and (ACE) (multiple body-orders), scales ( N ) ν where + 1 is body-order radial basis functions used in density expansion. We introduce two distinct approaches which can be to overcome this for spectrum. Firstly, we show that amenable lossless compression respect both , so descriptor reduced from $${{{\mathcal{O}}}}({N}^{2}{S}^{2})$$ O ( N 2 S ) $${{{\mathcal{O}}}}\left(NS\right)$$ . Secondly, a generalised kernel, achieved through use total, element agnostic density, combination projection. The ideas kernel equally applicably any other demonstrate (ACSF).