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Updated: Aug 20, 2026

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
Atom distributions in binary atom clusters: a perturbational approach and its validation in a case study
Florian Weigend1, Claudia Schrodt, Reinhart Ahlrichs
1Forschungszentrum Karlsruhe GmbH, Institut für Nanotechnologie, Postfach 3640, 76021 Karlsruhe, Germany. florian.weigend@int.fzk.de
Abstract:
An approach to describe heteroatomic clusters A(n)B(N-n) as perturbed homoatomic ones is presented. By first treating the homoatomic systems A(N) or/and B(N) and subsequent application of first-order perturbation theory it is possible to estimate relative stabilities of the 2(N) possible distributions of the atom types A and B at the N atomic sites in a very efficient manner. The approach was tested considering Ir(n)Pt(13-n) as an example (treated with density functional methods). One observes good correlation between relative stabilities estimated from the homoatomic cases and those obtained from explicit treatments of the binary systems. Moreover we rationalize the observed correlation of atom type and atom position in Ir(n)Pt(13-n).
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