Molecular Wires: Charge Injection, Charge Transport and Motion Mechanisms in DNA

2001 ◽  
Vol 679 ◽  
Author(s):  
Yu. A. Berlin ◽  
A. L. Burin ◽  
A. Nitzan ◽  
V. Mujica ◽  
A. Xue ◽  
...  
Keyword(s):  
Charge Transport ◽  
First Principles ◽  
Degrees Of Freedom ◽  
Experimental Studies ◽  
Charge Injection ◽  
Molecular Wires ◽  
Molecular Wire ◽  
Dna Duplex ◽  
Experimental Findings ◽  
Hopping Model

The use of the DNA duplex as a molecular wire is discussed with particular attention to recent experimental findings. Experimental studies of photo-excited hole dynamics in DNA can be understood within the phenomenological hopping model. However a microscopic first principles approach requires taking into account the interaction between charge and duplex degrees of freedom. The nature of possible metallic native DNA behavior is discussed.

scholarly journals Charge transport through extended molecular wires with strongly correlated electrons

2021 ◽  
Author(s):  
James O. Thomas ◽  
Jakub K. Sowa ◽  
Bart Limburg ◽  
Xinya Bian ◽  
Charalambos Evangeli ◽  
...  
Keyword(s):  
Electron Transport ◽  
Charge Transport ◽  
Experimental Studies ◽  
Strongly Correlated Electrons ◽  
Molecular Wires ◽  
Correlated Electrons ◽  
Strongly Correlated

Experimental studies of electron transport through an edge-fused porphyrin oligomer in a graphene junction are interpreted within a Hubbard dimer framework.

scholarly journals Towards a First-Principles Evaluation of Transport Mechanisms in Molecular Wires

2020 ◽  
Author(s):  
Susanne kröncke ◽  
Carmen Herrmann
Keyword(s):  
Charge Transport ◽  
First Principles ◽  
Density Functional ◽  
Mixed Valence ◽  
Maximum Error ◽  
Molecular Wires ◽  
Polarizable Continuum Model ◽  
Charge Delocalization ◽  
Nanoscale Electronics ◽  
Transition Length

Understanding charge transport through molecular wires is important for nanoscale electronics and biochemistry. Our goal is to establish a simple first-principles protocol for predicting the charge transport mechanism in such wires, in particular the crossover from coherent tunneling for short wires to incoherent hopping for longer wires. This protocol is based on a combination of density-functional theory with a polarizable continuum model introduced by Kaupp et al. for mixed-valence molecules, which we had previously found to work well for length-dependent charge delocalization in such systems. We combine this protocol with a new charge delocalization measure tailored for molecular wires, and we show that it can predict the tunneling-to hopping transition length with a maximum error of one subunit in five sets of molecular wires studied experimentally in molecular junctions at room temperature. This suggests that the protocol is also well suited for estimating the extent of hopping sites as relevant, e.g., for the intermediate tunneling-hopping regime in DNA.

scholarly journals Towards a First-Principles Evaluation of Transport Mechanisms in Molecular Wires

2020 ◽  
Author(s):  
Susanne kröncke ◽  
Carmen Herrmann
Keyword(s):  
Charge Transport ◽  
First Principles ◽  
Density Functional ◽  
Mixed Valence ◽  
Maximum Error ◽  
Molecular Wires ◽  
Polarizable Continuum Model ◽  
Charge Delocalization ◽  
Nanoscale Electronics ◽  
Transition Length

Understanding charge transport through molecular wires is important for nanoscale electronics and biochemistry. Our goal is to establish a simple first-principles protocol for predicting the charge transport mechanism in such wires, in particular the crossover from coherent tunneling for short wires to incoherent hopping for longer wires. This protocol is based on a combination of density-functional theory with a polarizable continuum model introduced by Kaupp et al. for mixed-valence molecules, which we had previously found to work well for length-dependent charge delocalization in such systems. We combine this protocol with a new charge delocalization measure tailored for molecular wires, and we show that it can predict the tunneling-to hopping transition length with a maximum error of one subunit in five sets of molecular wires studied experimentally in molecular junctions at room temperature. This suggests that the protocol is also well suited for estimating the extent of hopping sites as relevant, e.g., for the intermediate tunneling-hopping regime in DNA.

scholarly journals Structural and physical properties of 99 complex bulk chalcogenides crystals using first-principles calculations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sahib Hasan ◽  
Khagendra Baral ◽  
Neng Li ◽  
Wai-Yim Ching
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
First Principles ◽  
Experimental Studies ◽  
First Principles Calculations ◽  
Chalcogenide Semiconductors ◽  
Optical And Mechanical Properties ◽  
Very Large Database ◽  
Unique Composition ◽  
Fundamental Physical

AbstractChalcogenide semiconductors and glasses have many applications in the civil and military fields, especially in relation to their electronic, optical and mechanical properties for energy conversion and in enviormental materials. However, they are much less systemically studied and their fundamental physical properties for a large class chalcogenide semiconductors are rather scattered and incomplete. Here, we present a detailed study using well defined first-principles calculations on the electronic structure, interatomic bonding, optical, and mechanical properties for 99 bulk chalcogenides including thirteen of these crytals which have never been calculated. Due to their unique composition and structures, these 99 bulk chalcogenides are divided into two main groups. The first group contains 54 quaternary crystals with the structure composition (A2BCQ4) (A = Ag, Cu; B = Zn, Cd, Hg, Mg, Sr, Ba; C = Si, Ge, Sn; Q = S, Se, Te), while the second group contains scattered ternary and quaternary chalcogenide crystals with a more diverse composition (AxByCzQn) (A = Ag, Cu, Ba, Cs, Li, Tl, K, Lu, Sr; B = Zn, Cd, Hg, Al, Ga, In, P, As, La, Lu, Pb, Cu, Ag; C = Si, Ge, Sn, As, Sb, Bi, Zr, Hf, Ga, In; Q = S, Se, Te; $$\hbox {x} = 1$$ x = 1 , 2, 3; $$\hbox {y} = 0$$ y = 0 , 1, 2, 5; $$\hbox {z} = 0$$ z = 0 , 1, 2 and $$\hbox {n} = 3$$ n = 3 , 4, 5, 6, 9). Moreover, the total bond order density (TBOD) is used as a single quantum mechanical metric to characterize the internal cohesion of these crystals enabling us to correlate them with the calculated properties, especially their mechanical properties. This work provides a very large database for bulk chalcogenides crucial for the future theoretical and experimental studies, opening opportunities for study the properties and potential application of a wide variety of chalcogenides.

scholarly journals Hydrogenation and oxidation enhances the thermoelectric performance of Si2BN monolayer

2021 ◽  
Author(s):  
H. R. Mahida ◽  
Deobrat Singh ◽  
Yogesh Sonvane ◽  
Sanjeev K. Gupta ◽  
P. B. Thakor ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Charge Transport ◽  
Transport Properties ◽  
First Principles ◽  
Density Functional ◽  
Thermoelectric Performance ◽  
First Principles Calculations ◽  
Functional Theory

In the present study, we have investigated the structural, electronic, and charge transport properties of pristine, hydrogenated, and oxidized Si2BN monolayers via first-principles calculations based on density functional theory (DFT).

scholarly journals The Influence of Alcohol Consumption on Fighting, Shoplifting and Vandalism in Young Adults

2021 ◽  
Vol 18 (7) ◽  
pp. 3509
Author(s):  
Ieuan Evans ◽  
Jon Heron ◽  
Joseph Murray ◽  
Matthew Hickman ◽  
Gemma Hammerton
Keyword(s):  
Young Adults ◽  
Longitudinal Study ◽  
Alcohol Consumption ◽  
Experimental Studies ◽  
Real Life ◽  
Self Report ◽  
Parents And Children ◽  
Experimental Findings ◽  
Avon Longitudinal Study ◽  
Causal Component

Experimental studies support the conventional belief that people behave more aggressively whilst under the influence of alcohol. To examine how these experimental findings manifest in real life situations, this study uses a method for estimating evidence for causality with observational data—‘situational decomposition’ to examine the association between alcohol consumption and crime in young adults from the Avon Longitudinal Study of Parents and Children. Self-report questionnaires were completed at age 24 years to assess typical alcohol consumption and frequency, participation in fighting, shoplifting and vandalism in the previous year, and whether these crimes were committed under the influence of alcohol. Situational decomposition compares the strength of two associations, (1) the total association between alcohol consumption and crime (sober or intoxicated) versus (2) the association between alcohol consumption and crime committed while sober. There was an association between typical alcohol consumption and total crime for fighting [OR (95% CI): 1.47 (1.29, 1.67)], shoplifting [OR (95% CI): 1.25 (1.12, 1.40)], and vandalism [OR (95% CI): 1.33 (1.12, 1.57)]. The associations for both fighting and shoplifting had a small causal component (with the association for sober crime slightly smaller than the association for total crime). However, the association for vandalism had a larger causal component.

Polaron Effects on Charge Transport through Molecular Wires: A Multiscale Approach

2016 ◽  
Vol 13 (1) ◽  
pp. 286-296 ◽  
Author(s):  
Tomáš Kubař ◽  
Marcus Elstner ◽  
Bogdan Popescu ◽  
Ulrich Kleinekathöfer
Keyword(s):  
Charge Transport ◽  
Molecular Wires ◽  
Multiscale Approach

scholarly journals Model Calibration for a Rigid Hexapod-Based End-Effector with Integrated Force Sensors

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3537
Author(s):  
Christian Friedrich ◽  
Steffen Ihlenfeldt
Keyword(s):  
Parameter Identification ◽  
Degrees Of Freedom ◽  
Force Measurement ◽  
Experimental Studies ◽  
Measurement Model ◽  
Calibration Procedure ◽  
Force Sensors ◽  
End Effector ◽  
Measurement Models ◽  
Fast Procedure

Integrated single-axis force sensors allow an accurate and cost-efficient force measurement in 6 degrees of freedom for hexapod structures and kinematics. Depending on the sensor placement, the measurement is affected by internal forces that need to be compensated for by a measurement model. Since the parameters of the model can change during machine usage, a fast and easy calibration procedure is requested. This work studies parameter identification procedures for force measurement models on the example of a rigid hexapod-based end-effector. First, measurement and identification models are presented and parameter sensitivities are analysed. Next, two excitation strategies are applied and discussed: identification from quasi-static poses and identification from accelerated continuous trajectories. Both poses and trajectories are optimized by different criteria and evaluated in comparison. Finally, the procedures are validated by experimental studies with reference payloads. In conclusion, both strategies allow accurate parameter identification within a fast procedure in an operational machine state.

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