The interaction of chemical bonds. IV. Interbond charge transfer by a coupled-cluster-type formalism

1995 ◽  
Vol 55 (2) ◽  
pp. 109-116 ◽  
Author(s):  
Péter R. Surján
Keyword(s):  
Charge Transfer ◽  
Coupled Cluster ◽  
Chemical Bonds ◽  
Cluster Type

scholarly journals A New Benchmark Set for Excitation Energy of Charge Transfer States: Systematic Investigation of Coupled Cluster Type Methods

2020 ◽  
Vol 16 (7) ◽  
pp. 4213-4225 ◽  
Author(s):  
Balázs Kozma ◽  
Attila Tajti ◽  
Baptiste Demoulin ◽  
Róbert Izsák ◽  
Marcel Nooijen ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Excitation Energy ◽  
Systematic Investigation ◽  
Coupled Cluster ◽  
Cluster Type

Coupled-pair theories and Davidson-type corrections for quasidegenerate states: The H4 model revisited

1988 ◽  
Vol 53 (9) ◽  
pp. 1919-1942 ◽  
Author(s):  
Josef Paldus ◽  
Paul E. S. Wormer ◽  
Marc Benard
Keyword(s):  
Electron Correlation ◽  
Model System ◽  
Coupled Cluster ◽  
Electron Model ◽  
Hydrogen Molecules ◽  
Double Zeta ◽  
Correlation Problem ◽  
Variational Approaches ◽  
Cluster Type ◽  
The Many

The performance of various variational and non-variational approaches to the many-electron correlation problem is examined for a simple four-electron model system consisting of two stretched hydrogen molecules in trapezoidal, rectangular and linear configurations, in which the degree of quasi-degeneracy can be continuously varied from a non-degenerate to an almost degenerate situation. In contrast to an earlier work (K. Jankowski and J. Paldus, Int. J. Quantum Chem. 18, 1243 (1980)) we employ a double-zeta plus polarization basis and examine both single reference and multireference configuration interaction and coupled-cluster-type approaches. The performance of various Davidson-type corrections is also investigated.

scholarly journals A feasible approach for automatically differentiable unitary coupled-cluster on quantum computers

2021 ◽  
Author(s):  
Jakob S. Kottmann ◽  
Abhinav Anand ◽  
Alán Aspuru-Guzik
Keyword(s):  
Coupled Cluster ◽  
Quantum Computers ◽  
Evaluation Procedures ◽  
Cluster Type

We develop computationally affordable and encoding independent gradient evaluation procedures for unitary coupled-cluster type operators, applicable on quantum computers.

scholarly journals A New Benchmark Set for Excitation Energy of Charge Transfer States: Systematic Investigation of Coupled-Cluster Type Methods

2020 ◽  
Author(s):  
Balázs Kozma ◽  
Attila Tajti ◽  
Baptiste Demoulin ◽  
Róbert Izsák ◽  
Marcel Nooijen ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Excitation Energy ◽  
Systematic Investigation ◽  
Coupled Cluster ◽  
Excitation Energies ◽  
Chemical Methods ◽  
Valence States ◽  
Quantum Chemical Methods ◽  
Material Physics ◽  
Cluster Methods

There are numerous publications on benchmarking quantum chemistry methods for excited states. These studies rarely include Charge Transfer (CT) states although many interesting phenomena in e.g. biochemistry and material physics involve transfer of electron between fragments of the system. Therefore, it is timely to test the accuracy of quantum chemical methods for CT states, as well. In this study we first suggest a set benchmark systems consisting of dimers having low-energy CT states. On this set, the excitation energy has been calculated with coupled cluster methods including triple excitations (CC3, CCSDT-3, CCSD(T)(a)* ), as well as with methods including full or approximate doubles (CCSD, STEOM-CCSD, CC2, ADC(2), EOM-CCSD(2)). The results show that the popular CC2 and ADC(2) methods are much more inaccurate for CT states than for valence states. On the other hand, CCSD seems to have similar systematic overestimation of the excitation energies for both valence and CT states. Concerning triples methods, the new CCSD(T)(a)* method including non-iterative triple excitations preforms very well for all type of states, delivering essentially CCSDT quality results.<br>

scholarly journals Role of interfacial charge transfer process in the graphene-ZnO-MoO3 core-shell nanoassemblies for efficient disinfection of industrial effluents

2019 ◽  
Vol 13 (4) ◽  
pp. 376-386
Author(s):  
Rakkesh Ajay ◽  
Dhinasekaran Durgalakshmi ◽  
Ponnuraj Karthe ◽  
Subramanian Balakumar
Keyword(s):  
Charge Transfer ◽  
Photocatalytic Performance ◽  
Graphene Nanosheets ◽  
Electronic Conductivity ◽  
Reaction Medium ◽  
Core Shell ◽  
Chemical Bonds ◽  
Interfacial Charge Transfer ◽  
Synthesis Strategy ◽  
Interfacial Charge

A combined wet chemical strategy was adopted to fabricate size controllable ZnO-MoO3 core-shell nanostructures by varying the surface potential in the reaction medium. The layered MoO3 was adsorbed on the surface of ZnO particles by electrostatic interaction and simultaneously anchored onto graphene nanosheets (GNS) by chemical bonds. The sunlight induced photocatalytic phenomena of the GNS-ZnO-MoO3 hybrid nanoassemblies have been examined by photodegradation of harmful organic pollutant. As a result, the as-synthesized GNS-ZnO-MoO3 hybrid nanoassemblies showed a better photocatalytic performance towards acridine orange dye (AO). The efficient photocatalytic performance was due to the interfacial charge transfer processes between GNS and ZnO-MoO3 that improves the electronic conductivity of the hybrid nanostructure. Moreover, the chemical bonds formed between the MoO3 shells and GNS efficiently hinder the recombination loss of photogenerated charges. This synthesis strategy was very simple, effective and can be extended to assembling other ternary nanostructures with enhanced photodegradation performance.

scholarly journals Ultrafast photoactivation of C─H bonds inside water-soluble nanocages

2019 ◽  
Vol 5 (2) ◽  
pp. eaav4806 ◽  
Author(s):  
Ankita Das ◽  
Imon Mandal ◽  
Ravindra Venkatramani ◽  
Jyotishman Dasgupta
Keyword(s):  
Charge Transfer ◽  
Degrees Of Freedom ◽  
Bond Cleavage ◽  
Electron Transfer Reaction ◽  
Water Soluble ◽  
Charge Transfer Complexes ◽  
Chemical Bonds ◽  
Proton Coupled Electron Transfer ◽  
Selective Reaction ◽  
Carbon Centered Radical

Light energy absorbed by molecules can be harnessed to activate chemical bonds with extraordinary speed. However, excitation energy redistribution within various molecular degrees of freedom prohibits bond-selective chemistry. Inspired by enzymes, we devised a new photocatalytic scheme that preorganizes and polarizes target chemical bonds inside water-soluble cationic nanocavities to engineer selective functionalization. Specifically, we present a route to photoactivate weakly polarized sp3C─H bonds in water via host-guest charge transfer and control its reactivity with aerial O2. Electron-rich aromatic hydrocarbons self-organize inside redox complementary supramolecular cavities to form photoactivatable host-guest charge transfer complexes in water. An ultrafast C─H bond cleavage within ~10 to 400 ps is triggered by visible-light excitation, through a cage-assisted and solvent water–assisted proton-coupled electron transfer reaction. The confinement prolongs the lifetime of the carbon-centered radical to enable a facile yet selective reaction with molecular O2leading to photocatalytic turnover of oxidized products in water.

Enhanced NO2 sensing performance of S-doped biomorphic SnO2 with increased active sites and charge transfer at room temperature

2020 ◽  
Vol 7 (10) ◽  
pp. 2031-2042
Author(s):  
Wenna Li ◽  
Lang He ◽  
Xue Bai ◽  
Lujia Liu ◽  
Muhammad Ikram ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Active Sites ◽  
Room Temperature ◽  
Gas Sensing ◽  
Chemical Bonds ◽  
Sensing Performance

S-Doped biomorphic SnO2 with active S-terminations and S–Sn–O chemical bonds has significantly improved gas sensing performance to NO2 at room temperature.

Interaction between Carbon Nanotube and Mg Surface: Ab-Initio Investigation

2007 ◽  
Vol 546-549 ◽  
pp. 481-484
Author(s):  
Jian Feng Wan ◽  
Yan Qiong Fei ◽  
Jian Nong Wang
Keyword(s):  
Charge Transfer ◽  
Carbon Nanotube ◽  
Ab Initio ◽  
Density Of States ◽  
Electronic Structures ◽  
Metal Surfaces ◽  
Bond Order ◽  
Chemical Bonds ◽  
Single Walled Carbon Nanotube ◽  
Work Functions

ab-initio calculations on the interaction between the single-walled carbon nanotube (SWCN) and the Mg (0001) surface have been reported. It was found that the charge transfer from metal surfaces to the nanotubes takes place depending on both the electronic structures of the nanotubes and the work functions of the metal surfaces. The stable geometries for the nanotube between two consecutive objectives with C-Mg chemical bonds formed. The interaction energy in the most stable geometry is found to be CNT’s structural dependence. Concerning the electronic properties, the most stable structure showed a decrease in the density of states near the Fermi level due to the formation of C-Mg bonds enhancing the metallic character of the nanotube by the contact with the surface. The nature of the nanotube-interface interaction for nanotubes of larger diameters has been also discussed based on the calculated bond order.

Sign in / Sign up

Export Citation Format

Share Document