Abstract
Atomic radius is a fundamentally important quantity shaping multiple properties of atoms, molecules, and materials. Due to its fundamental importance, precise quantification and interpretation of atomic radii has been the subject of numerous studies for more than a century. It has resulted in a broad variety of estimations of atomic radii which so far have not been amenable to extensive verification by experiment. The present study follows our recent work demonstrating that electron iso-density surfaces, contoured at a certain cut-off density, accurately represent molecular surfaces determined via thermodynamic phase change data. Here we provide thermodynamically consistent estimates of atomic radii for the main group elements.