Dipped adcluster model study for the end-on chemisorption of O2 on an Ag surface

1992 ◽  
Vol 70 (2) ◽  
pp. 404-408 ◽  
Author(s):  
Hiroshi Nakatsuji ◽  
Hiromi Nakai
Keyword(s):  
Ground State ◽  
Cluster Model ◽  
Lower Energy ◽  
Theoretical Study ◽  
Coupling Model ◽  
Spin Coupling ◽  
Adsorbed Species ◽  
Net Charge ◽  
Model Study ◽  
Lower Energy Region

Theoretical study for the end-on adsorption of an O2 molecule on an Ag surface is carried out with the use of the dipped adcluster model (DAM). The adcluster of AgO2 is taken and the highest spin coupling model is employed. Electron transfer from the bulk metal to the adcluster considered by DAM is important for the occurrence of the chemisorption, and this cannot be described by the small-size cluster model. Electron correlations are also quite important and are described by the SD-CI method based on the corresponding parent configurations. In the end-on geometry, the superoxide species is the ground state, and there are no peroxide species in the lower energy region. The calculated adsorption energy compares reasonably with the experimental value. The O—O axis of the superoxide is inclined by 70°–80° from the surface normal. The outside oxygen atom of the adsorbed species seems to be more reactive than the inside one, while the net charge on the former is smaller than that on the latter. Keywords: DAM (dipped adcluster model), silver, superoxide, chemisorption.

Structures and Electronic Spectroscopy of Rhodium-Based Complexes: a Theoretical Study on Promising Optical Materials

2011 ◽  
Vol 284-286 ◽  
pp. 2288-2291
Author(s):  
Yuan Ru Guo ◽  
Qing Jiang Pan
Keyword(s):  
Photocatalytic Activity ◽  
Lower Energy ◽  
Optical Materials ◽  
Theoretical Study ◽  
Electronic Spectroscopy ◽  
Bidentate Ligand ◽  
Structural Description ◽  
Td Dft ◽  
Lower Energy Region ◽  
Fine Tune

A series of rhodium-based complexes were explored theoretically to understand their application in optical materials and potential photocatalytic activity. Better structural description of [RhAu(CNH)2(PH2CH2PH2)2]2+ (1) were achieved with the ab initio MP2, XαVWN, and SVWN methods. To fine-tune the electronic spectroscopy, two analogues of 1 were taken into account by varying its Au metal center and bridging bidentate ligand. The experimental spectra were well reproduced by our TD-DFT calculations. It was shown that the lowest-energy absorption of homobimetallic Rh-Rh complex occurs in lower-energy region than those of heterobimetallic Rh-Au complexes.

POLARON IN A QUANTUM DOT UNDER AN ELECTRIC FIELD

2007 ◽  
Vol 21 (24) ◽  
pp. 1635-1642
Author(s):  
MIAN LIU ◽  
WENDONG MA ◽  
ZIJUN LI
Keyword(s):  
Quantum Dot ◽  
Electric Field ◽  
Field Intensity ◽  
Ground State Energy ◽  
Ground State ◽  
Electric Field Intensity ◽  
State Energy ◽  
Theoretical Study ◽  
The Moment ◽  
Transformation Methods

We conducted a theoretical study on the properties of a polaron with electron-LO phonon strong-coupling in a cylindrical quantum dot under an electric field using linear combination operator and unitary transformation methods. The changing relations between the ground state energy of the polaron in the quantum dot and the electric field intensity, restricted intensity, and cylindrical height were derived. The numerical results show that the polar of the quantum dot is enlarged with increasing restricted intensity and decreasing cylindrical height, and with cylindrical height at 0 ~ 5 nm , the polar of the quantum dot is strongest. The ground state energy decreases with increasing electric field intensity, and at the moment of just adding electric field, quantum polarization is strongest.

Theoretical Study of the Binding of the Thiol-Containing Cysteine Amino Acid to the Silver Surface Using a Cluster Model

2021 ◽  
Vol 125 (16) ◽  
pp. 3244-3256
Author(s):  
Pham Vu Nhat ◽  
Nguyen Thanh Si ◽  
Nguyen Thanh Tien ◽  
Minh Tho Nguyen
Keyword(s):  
Amino Acid ◽  
Cluster Model ◽  
Theoretical Study ◽  
Silver Surface ◽  
Cysteine Amino Acid

VUV FRAGMENTATION OF SOME HYDROFLUOROCARBON CATIONS STUDIED USING COINCIDENCE TECHNIQUES

2002 ◽  
Vol 09 (01) ◽  
pp. 153-158 ◽  
Author(s):  
WEIDONG ZHOU ◽  
D. P. SECCOMBE ◽  
R. Y. L. CHIM ◽  
R. P. TUCKETT
Keyword(s):  
Kinetic Energy ◽  
Ab Initio ◽  
Ground State ◽  
Lower Energy ◽  
Lone Pair ◽  
Electronic States ◽  
Photoelectron Spectra ◽  
Highest Occupied Molecular Orbital ◽  
Impulsive Model ◽  
Lone Pair Electrons

Threshold photoelectron–photoion coincidence (TPEPICO) spectroscopy has been used to investigate the decay dynamics of the valence electronic states of the parent cation of several hydrofluorocarbons (HFC), based on fluorine-substituted ethane, in the energy range 11–25 eV. We present data for CF 3– CHF 2, CF 3– CH 2 F , CF 3– CH 3 and CHF 2– CH 3. The threshold photoelectron spectra (TPES) of these molecules show a common feature of a broad, relatively weak ground state, associated with electron removal from the highest-occupied molecular orbital (HOMO) having mainly C–C σ-bonding character. Adiabatic and vertical ionisation energies for the HOMO of the four HFCs are presented, together with corresponding values from ab initio calculations. For those lower-energy molecular orbitals associated with non-bonding fluorine 2pπ lone pair electrons, these electronic states of the HFC cation decay impulsively by C–F bond fission with considerable release of translational kinetic energy. Appearance energies are presented for formation of the daughter cation formed by such a process (e.g. CF 3– CHF +), together with ab initio energies of the corresponding dissociation channel (e.g. CF 3– CHF + + F ). Values for the translational kinetic energy released are compared with the predictions of a pure-impulsive model.

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