Abstract:
One- and two-component (spin–orbit coupled) relativistic and nonrelativistic energy adjusted
pseudopotentials and basis sets for the elements 111 and 112 are presented. Calculations on the
positively charged monohydride of the recently discovered superheavy element 112 are reported.
Electron correlation is treated at the multireference configuration interaction and coupled cluster
level and fine structure effects are derived from a single-reference configuration interaction
treatment. Relativistic effects decrease the (112) H+ bond distance by 0.41 Å. This bond contraction
is similar to the one calculated recently for (111) H [Chem. Phys. Lett. 250, 461 (1996)]. As a result
the bond distance of (112)H1 (1.52 Å) is predicted to be smaller compared to those of the hydrides
of the lighter congeners HgH1 (1.59 Å), CdH1 (1.60 Å) and similar to that of ZnH1 (1.52 Å).
We predict that (112)H1 is the most stable hydride in the Group 12 series due to relativistic effects.
As in the case of (111)H the relativistic increase of the stretching force constant is quite large,
from 1.5 to 4.3 mdyn/Å at the coupled cluster level. The trend in the dipole polarizabilities of
the Group 12 elements is discussed. Relativistic and electron correlation effects are nonadditive
and due to the relativistic ns contraction (n57 for 112), correlation effects out of the (n21)d core
are more important at the relativistic than the nonrelativistic level. We also show evidence
that element 112 behaves like a typical transition element, and as a consequence the high oxidation
state 14 in element 112 might be accessible.
