Atomic radii for atoms with the 6s shell outermost: The effective atomic radius and the van der Waals radius from Cs-55 to Hg-80

作者：Tatewaki Hiroshi^*; Hatano Yasuyo; Noro Takeshi; Yamamoto Shigeyoshi

来源：AIP Advances, 2015, 5(6): 067142.

DOI：10.1063/1.4922953

We consider, for atoms from Cs-55 to Hg-80, the effective atomic radius (r(ear)), which is defined as the distance from the nucleus at which the magnitude of the electric field is equal to that in He at one half of the equilibrium bond length of He-2. The values of r(ear) are about 50% larger than the mean radius of the outermost occupied orbital of 6s, <r(6s)>. The value of r(ear) decreases from Cs-55 to Ba-56 and undergoes increases and decreases with rising nuclear charge from La-57 to Yb-70. In fact r(ear) is understood as comprising two interlaced sequences; one consists of La-57, Ce-58, and Gd-64, which have electronic configuration (4f(n-1))(5d(1))(6s(2)), and the remaining atoms have configuration (4f(n))(6s(2)). The sphere defined by r(ear) contains 85%-90% of the 6s electrons. From Lu-71 to Hg-80 the radius r(ear) also involves two sequences, corresponding to the two configurations 5d(n+1)6s(1) and 5d(n)6s(2). The radius r(ear) according to the present methodology is considerably larger than r(vdW) obtained by other investigators, some of who have found values of r(vdW) close to <r(6s)>.

• 出版日期2015-6