First Exploration of Neutron Shell Structure below Lead and beyond N=126.

The nuclei below lead but with more than 126 neutrons are crucial to an understanding of the astrophysical r process in producing nuclei heavier than A∼190. Despite their importance, the structure and properties of these nuclei remain experimentally untested as they are difficult to produce in nuclear reactions with stable beams. In a first exploration of the shell structure of this region, neutron excitations in ^{207}Hg have been probed using the neutron-adding (d,p) reaction in inverse kinematics. The radioactive beam of ^{206}Hg was delivered to the new ISOLDE Solenoidal Spectrometer at an energy above the Coulomb barrier. The spectroscopy of ^{207}Hg marks a first step in improving our understanding of the relevant structural properties of nuclei involved in a key part of the path of the r process.

Electronic structure of bridging halogen atoms in metal halide dimers studied by the AM1 method and NQR spectroscopy.

A nuclear quadrupole resonance (NQR) study of the electronic structure of bridging halogen atoms in dimers of transition and non-transition metal halides has been performed. An explanation of the differences in the NQR frequencies for transition and non-transition metal halides is proposed. The population of the bridging halogen atom orbitals and the metal-halogen bond lengths have been estimated by the AM1 method. The aim of this paper was to obtain a relationship describing the lengths of the metal-halogen bonds.