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In contradiction to the prediction of the Periodic Table but in agreement with earlier suggestions by Brewer and Mann, the ground state configuration of atomic Lawrencium (Z = 103) will not be 7s2 6d 2D 3/2 but 7s2 7p 2P1/2. The reason for this deviation from normal trends across the Periodic Table are strong relativistic effects on the outermost 7p1/2 orbital. Multiconfiguration Dirac-Fock calculations are reported for Lawrencium and analogous lighter atoms. These calculations include contributions from magnetic and retardation interactions and an estimation of quantum electrodynamic corrections

CONCLUSIONS NMR studies can yield information on the dynamics of domain walls in materials where the signals arise from nuclei within domain walls. 'In addition, it has been shown that an NMR study can be used to study the static arrangement of spins within a domain wall somewhat quantitatively.In particular, it has been found that the strongly pinned domains in hematite having approximately 180' AF walls (which are difficult to remove with an applied field) are responsible for the largest contribution to the positive-phase NMR signal.The experimental data also suggest that the anomalous temperature dependence of M(T) may be related to these strongly pinned walls. It is suggested that careful magnetization measurements in extremely large fields might clear up this point.

Results of the DiracSlater discrete variational calculations for the group 4,5, and 6 highest chlorides including elements 104, 105, and 106 have shown that the groups are not identical with respect to trends in the electronic structure and bonding. The charge density distribution data show that notwithstanding the basic increase in covalency within the groups this increase diminishes in going from group 4 to group 6. As a result, E106C16 will be less stable toward thermal decomposition than W C L which is confirmed by an estimated low E 1 0 6 4 1 bond energy. AHform equal to -90.3 f 6 kcal/mol is obtained for ElO6Cl6 in the gas phase, which is indicative of a very low stability of this compound. The stability of the maximum oxidation state is shown to decrease in the direction E104(+4) > E105(+5) > E106(+6).

Results of relativistic multiconfiguration Dirac-Fock calculations with an extended nucleus are used to analyze the volume isotope shifts of the resonance transitions in the group-11a and-11 b elements as well as in Vb. This is done together with a review of the isotope shift theory, including a critical evaluation and comparison of the semiempirical calculation of volume isotope shifts commonly used today. Electronic factors F;, proportional to differences of electronic densities over the nuclear volume, are discussed within various approximations and compared with experimental results. r" over the nuclear charge distribution of the two nuclei. Expression (6) can be written in various ways:4,4Z-44

Multiconfiguration relativistic Dirac-Fock (MCDF) values have been computed for the first four ionization potentials (IPs) of element 104 (unnilquadium) and of the other group 4 elements (Ti, Zr, and Hf). Factors were calculated that allowed correction ofthe systematic errors between the MCDF IPs and the experimental IPs. Single "experimental" IPs evaluated in eV (to ± 0.1 eV) for element 104 are: [

Articles you may be interested inTime-dependent four-component relativistic density-functional theory for excitation energies. II. The exchangecorrelation kernel J. Chem. Phys. 123, 054102 (2005); 10.1063/1.1940609 Scalar relativistic all-electron density functional calculations on periodic systems J. Chem. Phys. 122, 084108 (2005); 10.1063/1.1851973 Response to "Comment on 'Four-component relativistic density functional calculations of heavy diatomic molecules'" [Comment on "Four-component relativistic density functional calculations of heavy diatomic molecules" [J. Chem.Molecular density functional calculations in the regular relativistic approximation: Method, application to coinage metal diatomics, hydrides, fluorides and chlorides, and comparison with first-order relativistic calculationsWe perform accurate four-component calculations for heavy closed-shell diatomic molecules in the framework of relativistic density functional theory using local and gradient corrected density functional schemes. As examples we have chosen Cu 2 , Ag 2 , Au 2 , Tl 2 , Pb 2 , Bi 2 , and Pt 2 . The potential energy curves show the quality, and the discrepancies of the density functionals unscreened from any approximation of the relativistic effects.