Quantum chemical study of small palladium clusters

TY - JOUR

T1 - Quantum chemical study of small palladium clusters

AU - Efremenko, Irena

AU - Sheintuch, Moshe

N1 - Funding Information: This research was supported by The Water Research Institute and by The Centre for Absorption in Science, Ministry of Immigrant Absorption, State of Israel. We thank Dr. D.M. Proserpio and P. Macchi from the University of Milan, Italy for providing the EH code.

PY - 1998/9/11

Y1 - 1998/9/11

N2 - The extended Hückel method with an electrostatic two-body correction has been used to find the structure of small Pdn clusters for n=2-13. Twins formation, with metal-metal bond lengths slightly smaller than those of bulk palladium, was found to be the preferential direction for cluster growth in the absence of external field. In accordance with the experimental results, these close-packed particles show a significant split in the valence d-zone. The energetic gap between HOMO and LUMO narrows from 3.217 to 0.68 eV as the cluster grows from two to 13 atoms. The LUMO has a bonding character toward Pd-Pd bonds, whereas HOMO is antibonding, so one can suggest that both donating and accepting interactions are favorable for strengthening of clusters. Occupation of 5s and 5p orbitals increases during cluster growth, while the net charge on the outer atoms remains very small. The results obtained for two to six atomic clusters are in good agreement with first principle calculations. Very close similarity with Rh cluster growth was observed.

AB - The extended Hückel method with an electrostatic two-body correction has been used to find the structure of small Pdn clusters for n=2-13. Twins formation, with metal-metal bond lengths slightly smaller than those of bulk palladium, was found to be the preferential direction for cluster growth in the absence of external field. In accordance with the experimental results, these close-packed particles show a significant split in the valence d-zone. The energetic gap between HOMO and LUMO narrows from 3.217 to 0.68 eV as the cluster grows from two to 13 atoms. The LUMO has a bonding character toward Pd-Pd bonds, whereas HOMO is antibonding, so one can suggest that both donating and accepting interactions are favorable for strengthening of clusters. Occupation of 5s and 5p orbitals increases during cluster growth, while the net charge on the outer atoms remains very small. The results obtained for two to six atomic clusters are in good agreement with first principle calculations. Very close similarity with Rh cluster growth was observed.

KW - Clusters

KW - Palladium

KW - Semi-empirical models and model calculations

UR - http://www.scopus.com/inward/record.url?scp=0032166929&partnerID=8YFLogxK

U2 - 10.1016/S0039-6028(98)00508-1

DO - 10.1016/S0039-6028(98)00508-1

M3 - 文章

AN - SCOPUS:0032166929

SN - 0039-6028

VL - 414

SP - 148

EP - 158

JO - Surface Science

JF - Surface Science

IS - 1-2

ER -