Refitted tetrahedral covalent radii for solids

The previous systems of molecular single-, double-, and triple-bond self-consistent, additive covalent radii R(AB) = r(A) + r(B) are now completed with a fit for crystals, where both atoms are tetrahedrally coordinated. A self-consistent primary fit is carried out using elements such as Si and binary compounds such as GaAs or ZnS. Further checks involve also ternary compounds such as chalcopyrites, CuInS₂, and the quaternary compounds Cu₂ZnSnS₄ and Cu₂ZnSnSe₄, the latter two with both kesterite and stannite structures. The input bond lengths R are taken from experimental or theoretical data. For the 30 elements in the primary fit, the mean-square deviation of the predicted R(AB) values is only 0.67 pm for the 48 systems used. The results are compared to earlier radii by Pauling and Huggins [Z. Kristallogr. A 87, 205 (1934)] or by Van Vechten and Phillips [Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.2.2160 2, 2160 (1970)], and to the recent molecular covalent radii.