https://doi.org/10.1140/epjd/e2014-40814-3
Regular Article
Theoretical study of the structures, stabilities, and electronic properties of neutral and anionic Ca2Siλn (n = 1-8, λ = 0, +1) clusters*
1
Department of Physics, Nanyang Normal University,
Nanyang
473061, P.R.
China
2
Department of Chemistry, State Key Laboratory of Applied Organic
Chemistry, Lanzhou University, Lanzhou
730000, P.R.
China
3
State Key Laboratory of Superhard Materials, Jilin
University, Changchun
130012, P.R.
China
a
e-mail: palc@163.com
Received:
19
December
2013
Received in final form:
12
February
2014
Published online: 29 April 2014
The structures, stabilities and electronic properties of neutral and cationic, calcium-doped, small silicon clusters Ca2Siλn (n = 1-8, λ = 0, +1) have been systematically investigated by using the density functional theory method at the B3LYP/6-311G (d) level. The results show that the ground state optimal structures of the cationic and neutral clusters favour the three-dimensional structures for n = 3−8 respectively, and that the cationic Ca2Sin+ clusters have the lowest-energy structures similar to those of neutral Ca2Sin clusters with the exception of Ca2Si6+. The main configurations of the Ca2Sin isomers are not affected by removal of an electron, but the order of their stability is reversed. Based on the optimised geometries, the averaged binding energy (Eb), fragmentation energy (Ef), second-order energy difference (Δ2E), HOMO-LUMO energy gap (Egap), adiabatic ionisation potential (AIP) and vertical ionisation potential (VIP) are analysed for the most stable structures. We found that Ca2Si5, Ca2Si7 and Ca2Si7+ clusters have the strongest relative stability, and that the positive charged clusters are more stable than the corresponding neutral ones.
Key words: Clusters and Nanostructures
Supplementary material in the form of one pdf file available from the Journal web page at http://dx.doi.org/10.1140/epjd/e2014-40814-3
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2014