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Electronic and Optical Properties of Small Metal Fluoride Clusters
Ist Teil von
ACS omega, 2020-06, Vol.5 (22), p.13268-13277
Ort / Verlag
American Chemical Society
Erscheinungsjahr
2020
Link zum Volltext
Quelle
EZB Electronic Journals Library
Beschreibungen/Notizen
We report a systematic
investigation on the electronic and optical
properties of the smallest stable clusters of alkaline-earth metal
fluorides, namely, MgF
2
, CaF
2
, SrF
2
, and BaF
2
. For these clusters, we perform density functional
theory (DFT) and time-dependent DFT (TDDFT) calculations with a localized
Gaussian basis set. For each molecule ((MF
2
)
n
,
n
= 1–3, M = Mg, Ca, Sr,
Ba), we determine a series of molecular properties, namely, ground-state
energies, fragmentation energies, electron affinities, ionization
energies, fundamental energy gaps, optical absorption spectra, and
exciton binding energies. We compare electronic and optical properties
between clusters of different sizes with the same metal atom and between
clusters of the same size with different metal atoms. From this analysis,
it turns out that MgF
2
clusters have distinguished ground-state
and excited-state properties with respect to the other fluoride molecules.
Sizeable reductions of the optical onset energies and a consistent
increase of excitonic effects are observed for all clusters under
study with respect to the corresponding bulk systems. Possible consequences
of the present results are discussed with respect to applied and fundamental
research.