Impact of solution temperature-dependent aggregation on the solid-state packing and electronic properties of polymers for organic photovoltaics

2018 ◽  
Vol 6 (48) ◽  
pp. 13162-13170 ◽  
Author(s):  
Ajith Ashokan ◽  
Tonghui Wang ◽  
Mahesh Kumar Ravva ◽  
Jean-Luc Brédas
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Electronic Properties ◽  
Organic Photovoltaics ◽  
Md Simulations ◽  
Solution Temperature ◽  
Temperature Dependent ◽  
The Impact

The impact of solution temperature-dependent aggregation of PffBT4T-2OD and PBT4T-2OD polymers on their electronic and solid-state packing properties is investigated using MD simulations and DFT calculations.

Defects of monolayer PbI2: a computational study

2021 ◽  
Vol 23 (36) ◽  
pp. 20553-20559
Author(s):  
Han Wang ◽  
Xiao Wang ◽  
Da Li
Keyword(s):  
Dft Calculations ◽  
Electronic Properties ◽  
Systematic Study ◽  
Computational Study ◽  
The Stability ◽  
The Impact

We performed a systematic study on the defects in PbI2 of both 1T and 1H phases by DFT calculations. The stability at the neutral and charged states was calculated. The impact of the defects on the electronic properties was also discussed.

Pressure-induced metallization of condensed-phase RDX: molecular dynamic simulations in conjunction with MSST method

2019 ◽  
Vol 97 (4) ◽  
pp. 245-253
Author(s):  
Zi-Qiu Bai ◽  
Jing Chang ◽  
Guang-Fu Ji ◽  
Ni-Na Ge
Keyword(s):  
Electronic Properties ◽  
Molecular Dynamic ◽  
Shock Loading ◽  
Md Simulations ◽  
Impact Sensitivity ◽  
Lower Sensitivity ◽  
Dynamic Simulations ◽  
Multi Scale ◽  
Cyclotrimethylene Trinitramine ◽  
The Impact

The anisotropy of impact sensitivity and microscopic electron properties of the cyclotrimethylene trinitramine (C3H6N6O6) (RDX) under shock loading are investigated in our work. The simulation is performed using molecular dynamic (MD) simulations in conjunction with multi-scale shock technique (MSST). By calculating the microscopic electronic properties and combining the thermodynamic properties, we predict that the metallization pressure of the RDX crystal is approximately 170 GPa under shock loading, which is slightly less than the metallization pressure under hydrostatic pressure. We also found that the microscopic electronic properties are related to the impact sensitivity. When the shock loading is along the z direction, the time of the transition from the insulating state to the metallization of the RDX crystal lags behind the shock loading along the x or y direction. Therefore, we predict that the RDX crystal has a lower sensitivity when the shock loading is along the z direction.

scholarly journals TrimethylamineN-oxide stabilizes proteins via a distinct mechanism compared with betaine and glycine

2017 ◽  
Vol 114 (10) ◽  
pp. 2479-2484 ◽  
Author(s):  
Yi-Ting Liao ◽  
Anthony C. Manson ◽  
Michael R. DeLyser ◽  
William G. Noid ◽  
Paul S. Cremer
Keyword(s):  
Surface Tension ◽  
Preferential Solvation ◽  
Water Structure ◽  
Md Simulations ◽  
Bulk Water ◽  
Solution Temperature ◽  
Water Interface ◽  
Hydrophobic Collapse ◽  
Folded Proteins ◽  
The Impact

We report experimental and computational studies investigating the effects of three osmolytes, trimethylamineN-oxide (TMAO), betaine, and glycine, on the hydrophobic collapse of an elastin-like polypeptide (ELP). All three osmolytes stabilize collapsed conformations of the ELP and reduce the lower critical solution temperature (LSCT) linearly with osmolyte concentration. As expected from conventional preferential solvation arguments, betaine and glycine both increase the surface tension at the air–water interface. TMAO, however, reduces the surface tension. Atomically detailed molecular dynamics (MD) simulations suggest that TMAO also slightly accumulates at the polymer–water interface, whereas glycine and betaine are strongly depleted. To investigate alternative mechanisms for osmolyte effects, we performed FTIR experiments that characterized the impact of each cosolvent on the bulk water structure. These experiments showed that TMAO red-shifts the OH stretch of the IR spectrum via a mechanism that was very sensitive to the protonation state of the NO moiety. Glycine also caused a red shift in the OH stretch region, whereas betaine minimally impacted this region. Thus, the effects of osmolytes on the OH spectrum appear uncorrelated with their effects upon hydrophobic collapse. Similarly, MD simulations suggested that TMAO disrupts the water structure to the least extent, whereas glycine exerts the greatest influence on the water structure. These results suggest that TMAO stabilizes collapsed conformations via a mechanism that is distinct from glycine and betaine. In particular, we propose that TMAO stabilizes proteins by acting as a surfactant for the heterogeneous surfaces of folded proteins.

Computationally Assisted Design of High Signal-to-Noise Photoinduced Electron Transfer-Based Voltage-Sensitive Dyes

2020 ◽  
Author(s):  
Rishikesh Kulkarni ◽  
Anneliese Gest ◽  
Chun Kei Lam ◽  
Benjamin Raliski ◽  
Feroz James ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Dft Calculations ◽  
Photoinduced Electron Transfer ◽  
Density Functional ◽  
Embryonic Stem ◽  
High Sensitivity ◽  
Md Simulations ◽  
High Signal ◽  
Signal To Noise ◽  
Green Fluorescent

<p>High signal-to-noise optical voltage indicators will enable simultaneous interrogation of membrane potential in large ensembles of neurons. However, design principles for voltage sensors with high sensitivity and brightness remain elusive, limiting the applicability of voltage imaging. In this paper, we use molecular dynamics (MD) simulations and density functional theory (DFT) calculations to guide the design of a bright and sensitive green-fluorescent voltage-sensitive fluorophore, or VoltageFluor (VF dye), that uses photoinduced electron transfer (PeT) as a voltage-sensing mechanism. MD simulations predict an 11% increase in sensitivity due to membrane orientation, while DFT calculations predict an increase in fluorescence quantum yield, but a decrease in sensitivity due to a decrease in rate of PeT. We confirm these predictions by synthesizing a new VF dye and demonstrating that it displays the expected improvements by doubling the brightness and retaining similar sensitivity to prior VF dyes. Combining theoretical predictions and experimental validation has resulted in the synthesis of the highest signal-to-noise green VF dye to date. We use this new voltage indicator to monitor the electrophysiological maturation of human embryonic stem cell-derived medium spiny neurons. </p>

Recent Advances of In-Silico Modeling of Potent Antagonists for the Adenosine Receptors

2019 ◽  
Vol 25 (7) ◽  
pp. 750-773 ◽  
Author(s):  
Pabitra Narayan Samanta ◽  
Supratik Kar ◽  
Jerzy Leszczynski
Keyword(s):  
Drug Targets ◽  
Biological Activities ◽  
Scoring Function ◽  
Md Simulations ◽  
Energy Calculation ◽  
Binding Modes ◽  
Macromolecular Systems ◽  
In Silico Modeling ◽  
Mathematical Algorithms ◽  
The Impact

The rapid advancement of computer architectures and development of mathematical algorithms offer a unique opportunity to leverage the simulation of macromolecular systems at physiologically relevant timescales. Herein, we discuss the impact of diverse structure-based and ligand-based molecular modeling techniques in designing potent and selective antagonists against each adenosine receptor (AR) subtype that constitutes multitude of drug targets. The efficiency and robustness of high-throughput empirical scoring function-based approaches for hit discovery and lead optimization in the AR family are assessed with the help of illustrative examples that have led to nanomolar to sub-micromolar inhibition activities. Recent progress in computer-aided drug discovery through homology modeling, quantitative structure-activity relation, pharmacophore models, and molecular docking coupled with more accurate free energy calculation methods are reported and critically analyzed within the framework of structure-based virtual screening of AR antagonists. Later, the potency and applicability of integrated molecular dynamics (MD) methods are addressed in the context of diligent inspection of intricated AR-antagonist binding processes. MD simulations are exposed to be competent for studying the role of the membrane as well as the receptor flexibility toward the precise evaluation of the biological activities of antagonistbound AR complexes such as ligand binding modes, inhibition affinity, and associated thermodynamic and kinetic parameters.

Temperature-Dependent Solid-state Luminescence and Reversible Phase Transition of (n-Bu4N)[Au(SC6H3-3,5-Me2)2]

2003 ◽  
Vol 32 (11) ◽  
pp. 1002-1003 ◽  
Author(s):  
Seiji Watase ◽  
Takayuki Kitamura ◽  
Nobuko Kanehisa ◽  
Masami Nakamoto ◽  
Yasushi Kai ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Temperature Dependent ◽  
Reversible Phase Transition ◽  
Reversible Phase ◽  
State Luminescence

Atomistic prediction on the configuration- and temperature-dependent dielectric constant of Be0.25Mg0.75O superlattice as a high-κ dielectric layer

2021 ◽  
Author(s):  
Gyuseung Han ◽  
In Won Yeu ◽  
Kun Hee Ye ◽  
Seung-Cheol Lee ◽  
Cheol Seong Hwang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dft Calculations ◽  
Bond Length ◽  
Dielectric Layer ◽  
Room Temperature ◽  
High Dielectric Constant ◽  
Temperature Dependent ◽  
High Dielectric

Through DFT calculations, a Be0.25Mg0.75O superlattice having long apical Be–O bond length is proposed to have a high bandgap (>7.3 eV) and high dielectric constant (∼18) at room temperature and above.

Insight into the formation of H-bonds propagating the monomeric zinc complexes of a tridentate reduced Schiff base to form an infinite chain

CrystEngComm ◽  
2021 ◽  
Author(s):  
Mainak Karmakar ◽  
Antonio Frontera ◽  
Shouvik Chattopadhyay
Keyword(s):  
Schiff Base ◽  
Solid State ◽  
Dft Calculations ◽  
Zinc Complexes ◽  
Infinite Chain ◽  
State Structure ◽  
Computational Tools ◽  
Solid State Structure ◽  
Reduced Schiff Base ◽  
Insight Into

The formation of an infinite 1D assembly is governed by the H-bonding interactions in the solid state structure of the two zinc complexes. It has been analyzed energetically using DFT calculations and several computational tools.

Synthesis, characterization, and temperature-dependent electronic properties of ZnO nanorods using CBD techniques

2021 ◽  
Author(s):  
C. A. Ruiz-Rojas ◽  
M. Aguilar-Frutis ◽  
F. Ramos-Brito ◽  
I. A. Garduño-Wilches ◽  
J. Narro-Ríos ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Zno Nanorods ◽  
Temperature Dependent
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