Extensive benchmarks of exchange-correlation functionals on real X-ray resolved nanoclusters have been carried out and reported here for the first time. The systems investigated and used for the tests are two undecagold and one Au24+-based nanoclusters stabilized by thiol and phosphine ligands. Time-dependent density-functional theory has been used to compare calculations with experimental data on optical gaps. It has been observed that GGA functionals employing PBE-like correlation (viz., PBE itself, B-PBE, B-P86, and B-PW91) coupled with an improved version of the LANL2DZ pseudopotential and basis set provide accurate results for both the structure and optical gap of gold nanoclusters, at a reasonable computational cost. Good geometries have been also obtained using some global hybrid (e.g., PBE0, B3-P86, mPW1-PW91) and range-separated hybrid (e.g., HSE06) functionals making use of PBE-like correlation, even though they yield optical gaps overestimating the experimental findings up to 0.5 eV. Popular exchange-correlation combinations such as B-LYP and B3-LYP deform cluster geometry during structural optimization, probably due to the LYP correlation. Effects of the stabilizing organic ligands on the properties of metal cores have been probed simulating the nanoclusters at the density-functional level of theory retaining the organic coating. This paper provides a useful contribution to the simulations of structural and optoelectronic properties of larger metal–organic particles suitable for a wide range of nanotechnological applications.
|Data di pubblicazione:||2014|
|Titolo:||Assessment of Exchange-Correlation Functionals in Reproducing the Structure and Optical Gap of Organic-Protected Gold Nanoclusters|
|Autore/i:||Francesco Muniz, Miranda; Menziani, Maria Cristina; Pedone, Alfonso|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1021/jp411483x|
|Codice identificativo ISI:||WOS:000334571700033|
|Codice identificativo Scopus:||2-s2.0-84898435916|
|Citazione:||Assessment of Exchange-Correlation Functionals in Reproducing the Structure and Optical Gap of Organic-Protected Gold Nanoclusters / Francesco Muniz, Miranda; Menziani, Maria Cristina; Pedone, Alfonso. - In: JOURNAL OF PHYSICAL CHEMISTRY. C. - ISSN 1932-7447. - ELETTRONICO. - 118(2014), pp. 7532-7544.|
|Tipologia||Articolo su rivista|
I documenti presenti in Iris Unimore sono rilasciati con licenza Creative Commons Attribuzione - Non commerciale - Non opere derivate 3.0 Italia, salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris