12 research outputs found
Neutral-ionic phase transition : a thorough ab-initio study of TTF-CA
The prototype compound for the neutral-ionic phase transition, namely TTF-CA,
is theoretically investigated by first-principles density functional theory
calculations. The study is based on three neutron diffraction structures
collected at 40, 90 and 300 K (Le Cointe et al., Phys. Rev. B 51, 3374 (1995)).
By means of a topological analysis of the total charge densities, we provide a
very precise picture of intra and inter-chain interactions. Moreover, our
calculations reveal that the thermal lattice contraction reduces the indirect
band gap of this organic semi-conductor in the neutral phase, and nearly closes
it in the vicinity of the transition temperature. A possible mechanism of the
neutral-ionic phase transition is discussed. The charge transfer from TTF to CA
is also derived by using three different technics.Comment: 11 pages, 9 figures, 7 table
Diatomáceas perifíticas em um sistema eutrófico brasileiro (Reservatório do Iraí, estado do Paraná)
Automated B-H curve identification algorithm combining field simulation with optimisation methods and exploiting parallel computation
Automated B–H curve identification algorithm combining field simulation with optimisation methods and exploiting parallel computation
International audienc
Effects of external yoke and clamping-plates on AC motor external field
International audienc