Abstract:
The study of the chemistry of superheavy elements through the application of theoretical teehniques is discussed. Parameters of relativistic, nonrelativistic and spin-orbit coupled pseudopotentials of elements 111 to 120 and accom-panying basis sets are presented. The nuclear stability of superheavy nuclei and the experimental investigation of the chemistry of these elements are briefly summarised. Relativistic molecular electronic structure techniques are reviewed with particular emphasis on their application to super-heavy elements. Relativistic effects on the properties of atoms are described. These effects are used to compare and explain the lanthanide and actinide contractions. Bonding theory in atoms of jj-coupled orbitals is described in detail. The properties of several compounds of elements 111, 112, 113 ,and 114 are calculated and discussed. Particular attention is paid to molecular geometries, bonding and the relative stability of the various oxidation states of each element. The behaviour of, each element is generally in accord with its predicted position in the periodic table. Pseudopotential results are found to be in excellent agreement with all-electron data for element 111 and in good agreement with all-electron results for elements 113 and 114. Relativistic effects are found to be very large for almost all molecules considered.