Electric field gradient and electronic properties of crown thioether compounds

Abstract

We compare published TDPAC experiments on 111 Cd in the crown thioether C 6 H 12 S 3 AgCl with ab-initio electronic structure calculations performed within the framework of the Density Functional Theory using the Projector Augmented Wave method. We conclude from this comparison that the Cd atom at the very moment of the TDPAC experiment is positively charged, and we point out to a methodological difference between reproducing experimental electric-field gradients in molecules versus solid metals.

Ionic exchange and the local structure in the HfO2/Ho2O3 system studied by PAC spectroscopy

“…Different experimental techniques, such as Nuclear Quadrupole Resonance (NQR), Nuclear Magnetic Resonance (NMR), Mössbauer Spectroscopy (MS), and Time-Differential c-c Perturbed-Angular-Correlation (PAC) spectroscopy, can be employed to study local electronic and structural properties at suitable probe-atom sites [22][23][24]. In particular, PAC has been extensively applied to study doped materials from the point of view of solid-state physics, chemistry, and biology in order to elucidate the subnanoscopic environment(s) of constituent or impurity atoms in solids, and the nature of chemical bonding in different kind of molecules and compounds [4,5,[25][26][27][28][29][30][31][32][33][34].…”

Metal coordination study at Ag and Cd sites in crown thioether complexes through DFT calculations and hyperfine parameters

“…Exchange and correlation (E xc ) effects were treated using the Perdew, Burke and Ernzearhof (GGA-PBE) functional [38]. The choice of the projectors, the cutoff energy criteria, and E xc functional were based on previous calculations [21,24,28,39,40], which also investigated EFG properties in molecules. All calculations were performed in the reciprocal space and the generated unit cell was chosen in order to be large enough to assure that the wave functions images did not interact with each other and decouple the spurious electrostatic interaction between molecules using a compensating charge background.…”

“…In 2005, Heinrich et al [23] used a DFT approach in order to establish a simple model to correlate the EFGs with the specific metal coordination environments in these complexes. The calculations were performed at the Ag sites, although the TDPAC measurements were performed at the 111 Cd nucleus after the 111 Ag→ 111 Cd nuclear decay [24][25][26]. Since the EFG is very sensitive to anisotropic charge distribution close to the probe nucleus, this decay can induce electronic and structural changes in the host molecules that was not taken into account by Heinrich et al [23].…”