Taesul Lee

Trends in hyperfine fields in alkali series

A relativistic many-body investigation has been carried out concerning the hyperfine field in the francium atom which is combined recently measured hyperfine constants to obtain accurate values of the magnetic moments of the isotopes 208-213Fr. A comparison of the francium results with other alkali atoms shows trends in the contributions from exchange polarisation and correlation effects over the alkali atom series, providing valuable insights into these mechanisms.

Influence of intermolecular bonding on nuclear quadrupole interaction tensors in solid halogens

The role of intermolecular bonding in solid halogens is studied using the self‐consistent charge extended Huckel procedure. It was found that the hybridization of s and d orbitals to p orbitals of the halogen plays a very important role in the intermolecular bonding. In particular it was found that the hybridization is stronger with (n+1) s and nd orbitals where n=3,4,5 for chlorine, bromine, and iodine than for ns orbitals. Using the ns, (n+1) s, np, and nd orbitals for the halogen atom and a number of its nearest neighbors, the wavefunctions of the interacting molecules have been calculated, and using these calculated wavefunctions, the field‐gradient tensors have been evaluated for all three systems. The asymmetry parameters are found to be 0.06, 0.18, 0.23 for chlorine, bromine, and iodine, respectively. The quadrupole coupling constants were found to be −109.10, −779.31, and −1923.97 MHz for chlorine, bromine, and iodine. Relativistic corrections have been incorporated in the evaluation of the field ...

Demonstration of charge transfer in “one-dimensional” organic metals☆

Abstract From a theoretical study of the energy-levels of the TCNQ and TTF molecules in the TTFTCNQ system and their counterparts in three other isostructural systems TSeFTCNQ, DSeDTFTCNQ ( cis and trans ) including the effect of Coulomb interactions with atomic charges on neighboring molecules, it is demonstrated quantitatively that sizeable fractional charge transfers are needed to explain the existence of common Fermi levels for the two chains in all four cases. The degrees of charge-transfers and location of the Fermi levels have been obtained in all four cases.