The article by Santiago Alvarez analyzes the distribution of distances from atoms of a particular element (E) to a probe atom (X, typically oxygen) in both bonded and intermolecular non-bonded contacts. The distribution is characterized by a maximum at short distances corresponding to chemical bonds, followed by a range of unpopulated distances (the van der Waals gap), and a second maximum at longer distances (the van der Waals peak). This distribution is superimposed on a random distribution function that roughly follows a d³ dependence. Alvarez proposes a consistent set of van der Waals radii for most naturally occurring elements, based on the analysis of over five million interatomic "non-bonded" distances. The applicability of these radii to other element pairs is tested using over three million data points, compared to over one million bond distances. The methodology involves extracting van der Waals radii for each element from the experimental distances of its intermolecular contacts with a reference element (X). The analysis considers spherical van der Waals atoms, disregarding details such as oxidation state and coordination number. The van der Waals radii are deduced from intermolecular distances to oxygen atoms, with some elements using other probe elements like nitrogen, deuterium, neon, xenon, and argon. The results show that van der Waals peaks are well-defined for most elements, with clear periodic trends in the proposed radii. The radii are generally consistent with those proposed by Bondi and Batsanov but differ significantly from those by Truhlar et al., which are based on computational studies and show wide fluctuations along the same period. The article also discusses the periodic trends of van der Waals radii, comparing them with covalent and ionic radii. The van der Waals radii are found to be 0.9 Å longer than the corresponding covalent radii, with the largest radius corresponding to the alkaline element. The periodic trends are roughly parallel to those of covalent radii, with some differences in the transition metals region. Overall, the study provides a comprehensive and consistent set of van der Waals radii for most naturally occurring elements, with implications for understanding molecular and crystal structures.The article by Santiago Alvarez analyzes the distribution of distances from atoms of a particular element (E) to a probe atom (X, typically oxygen) in both bonded and intermolecular non-bonded contacts. The distribution is characterized by a maximum at short distances corresponding to chemical bonds, followed by a range of unpopulated distances (the van der Waals gap), and a second maximum at longer distances (the van der Waals peak). This distribution is superimposed on a random distribution function that roughly follows a d³ dependence. Alvarez proposes a consistent set of van der Waals radii for most naturally occurring elements, based on the analysis of over five million interatomic "non-bonded" distances. The applicability of these radii to other element pairs is tested using over three million data points, compared to over one million bond distances. The methodology involves extracting van der Waals radii for each element from the experimental distances of its intermolecular contacts with a reference element (X). The analysis considers spherical van der Waals atoms, disregarding details such as oxidation state and coordination number. The van der Waals radii are deduced from intermolecular distances to oxygen atoms, with some elements using other probe elements like nitrogen, deuterium, neon, xenon, and argon. The results show that van der Waals peaks are well-defined for most elements, with clear periodic trends in the proposed radii. The radii are generally consistent with those proposed by Bondi and Batsanov but differ significantly from those by Truhlar et al., which are based on computational studies and show wide fluctuations along the same period. The article also discusses the periodic trends of van der Waals radii, comparing them with covalent and ionic radii. The van der Waals radii are found to be 0.9 Å longer than the corresponding covalent radii, with the largest radius corresponding to the alkaline element. The periodic trends are roughly parallel to those of covalent radii, with some differences in the transition metals region. Overall, the study provides a comprehensive and consistent set of van der Waals radii for most naturally occurring elements, with implications for understanding molecular and crystal structures.