Molecular Single‐Bond Covalent Radii for Elements 1–118

A self‐consistent system of additive covalent radii, R(AB)=r(A) + r(B), is set up for the entire periodic table, Groups 1–18, Z=1–118. The primary bond lengths, R, are taken from experimental or theoretical data corresponding to chosen group valencies. All r(E) values are obtained from the same fit. Both E–E, E–H, and E–CH₃ data are incorporated for most elements, E. Many E–E′ data inside the same group are included. For the late main groups, the system is close to that of Pauling. For other elements it is close to the methyl‐based one of Suresh and Koga J. Phys. Chem. A 2001 , 105, 5940] and its predecessors. For the diatomic alkalis MM′ and halides XX′, separate fits give a very high accuracy. These primary data are then absorbed with the rest. The most notable exclusion are the transition‐metal halides and chalcogenides which are regarded as partial multiple bonds. Other anomalies include H₂ and F₂. The standard deviation for the 410 included data points is 2.8 pm.