Static dipole polarizabilities for the ${}^{3}P_0$ ground state of the neutral group-14 elements C, Si, Ge, Sn, Pb and element $Z=114$ were obtained from all-electron relativistic coupled cluster theory, and compared to molecular beam electric field deflection experiments for Sn and Pb. The isotropic and anisotropic components of the polarizability increase monotonically with the nuclear charge $Z$, except for the spin-orbit coupled $J=0$ states, which start to decrease from Sn to Pb and even further to element $Z=114$. Hence, spin-orbit coupling leads to a significant reduction of the polarizability of element $Z=114$, i.e., from $47.9\mathrm{a.u.}$ at the scalar-relativistic Douglas-Kroll level to $31.5\mathrm{a.u.}$ at the Dirac-Coulomb level of theory, which is below the value of Si $\left(37.3\mathrm{a.u.}\right)$. The calculations further demonstrate that relativistic and electron correlation effects are nonadditive. The measured dipole polarizabilities of Sn and Pb are in reasonable agreement with the theoretical values.

• Received 14 July 2008

DOI:https://doi.org/10.1103/PhysRevA.78.052506