ct5003994_si_001.pdf (374.8 kB)
Toward a Quantitative Assessment of Electronic Transitions’ Charge-Transfer Character
journal contribution
posted on 2014-09-09, 00:00 authored by Thibaud Etienne, Xavier Assfeld, Antonio MonariWe hereby report studies devoted
to a topological descriptor of
photoinduced electronic charge density variation. Our novel index,
symbolized as ϕS, consists in the
detachment and attachment densities overlap, where the detachment
density physically depicts the electron density removed from the ground
state of a molecule during the transition while the attachment density
consists in the rearranged density in the excited state. Our method
provides a simple and efficient way to quantitatively evaluate how
easy the charge-separation is made upon the chromophore’s light
absorption. Furthermore, this model can be applied for instance to
address a comment on new push–pull dyes charge-transfer ability
in order to assess their potentiality as candidates for light absorption-based
devices. Moreover, the ϕS assessment
allows us to perform some methodological diagnostic tests concerning
the use of long-range corrected exchange–correlation functional
in a time-dependent density functional theory (TDDFT) framework. This
paper relates the ϕS descriptor’s
mathematical foundations from various perspectives (detachment/attachment
densities or natural transition orbitals), together with its application
to several types of chromophores. Connections and divergences with
a formerly proposed index are finally evidenced.