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Articles 1 - 29 of 29
Full-Text Articles in Entire DC Network
A Molecular Dynamics Study Of Monomer Melt Properties Of Cyanate Ester Monomer Melt Properties, Rebecca T. Haber, Andrea R. Browning, Bayleigh R. Graves, William P. Davis, Jeffrey S. Wiggins
A Molecular Dynamics Study Of Monomer Melt Properties Of Cyanate Ester Monomer Melt Properties, Rebecca T. Haber, Andrea R. Browning, Bayleigh R. Graves, William P. Davis, Jeffrey S. Wiggins
Faculty Publications
The objective of this work was to computationally predict the melting temperature and melt properties of thermosetting monomers used in aerospace applications. In this study, we applied an existing voids method by Solca. to examine four cyanate ester monomers with a wide range of melting temperatures. Voids were introduced into some simulations by removal of molecules from lattice positions to lower the free-energy barrier to melting to directly simulate the transition from a stable crystal to amorphous solid and capture the melting temperature. We validated model predictions by comparing melting temperature against previously reported literature values. Additionally, the torsion and …
Semiflexible Oligomers Crystallize Via A Cooperative Phase Transition, Pierre Kawak, Dakota S. Banks, Douglas R. Tree
Semiflexible Oligomers Crystallize Via A Cooperative Phase Transition, Pierre Kawak, Dakota S. Banks, Douglas R. Tree
Faculty Publications
Semicrystalline polymers are ubiquitous, yet despite their fundamental and industrial importance, the theory of homogeneous nucleation from a melt remains a subject of debate. A key component of the controversy is that polymer crystallization is a non-equilibrium process, making it difficult to distinguish between effects that are purely kinetic and those that arise from the underlying thermodynamics. Due to computational cost constraints, simulations of polymer crystallization typically employ non-equilibrium molecular dynamics techniques with large degrees of undercooling that further exacerbate the coupling between thermodynamics and kinetics. In a departure from this approach, in this study, we isolate the near-equilibrium nucleation …
Diffusional Fractionation Of Helium Isotopes In Silicate Melts, Haiyang Luo, Bijaya Karki, Dipta B. Ghosh, Huiming Bao
Diffusional Fractionation Of Helium Isotopes In Silicate Melts, Haiyang Luo, Bijaya Karki, Dipta B. Ghosh, Huiming Bao
Faculty Publications
Estimating Helium (He) concentration and isotope composition of the mantle requires quantifying He loss during magma degassing. The knowledge of diffusional He isotope fractionation in silicate melts may be essential to constrain the He loss. Isotopic mass dependence of He diffusion can be empirically expressed as D3He/D4He = (4/3)^β, where D is the diffusivity of a He isotope. However, no studies have reported any β values for He in silicate melts due to technical challenges in both experiments and computations. Here, molecular dynamics simulations based on deep neural network potentials trained by ab initio data …
Fate Of Hydrous Fe-Rich Silicate Melt In Earth's Deep Mantle, Zhixue Du, Jie Deng, Yoshinori Miyazaki, Ho Kwang Mao, Bijaya B. Karki, Kanani K.M. Lee
Fate Of Hydrous Fe-Rich Silicate Melt In Earth's Deep Mantle, Zhixue Du, Jie Deng, Yoshinori Miyazaki, Ho Kwang Mao, Bijaya B. Karki, Kanani K.M. Lee
Faculty Publications
Density of silicate melt dictates melt migration and establishes the gross structure of Earth's interior. However, due to technical challenges, the melt density of relevant compositions is poorly known at deep mantle conditions. Particularly, water may be dissolved in such melts in large amounts and can potentially affect their density at extreme pressure and temperature conditions. Here we perform first-principles molecular dynamics simulations to evaluate the density of Fe-rich, eutectic-like silicate melt (E melt) with varying water content up to about 12 wt %. Our results show that water mixes nearly ideally with the nonvolatile component in silicate melt and …
In Silico Identification Of Genetic Mutations Conferring Resistance To Acetohydroxyacid Synthase Inhibitors: A Case Study Of Kochia Scoparia, Yan Li, Michael D. Netherland, Chaoyang Zhang, Huixiao Hong, Ping Gong
In Silico Identification Of Genetic Mutations Conferring Resistance To Acetohydroxyacid Synthase Inhibitors: A Case Study Of Kochia Scoparia, Yan Li, Michael D. Netherland, Chaoyang Zhang, Huixiao Hong, Ping Gong
Faculty Publications
Mutations that confer herbicide resistance are a primary concern for herbicide-based chemical control of invasive plants and are often under-characterized structurally and functionally. As the outcome of selection pressure, resistance mutations usually result from repeated long-term applications of herbicides with the same mode of action and are discovered through extensive field trials. Here we used acetohydroxyacid synthase (AHAS) of Kochia scoparia (KsAHAS) as an example to demonstrate that, given the sequence of a target protein, the impact of genetic mutations on ligand binding could be evaluated and resistance mutations could be identified using a biophysics-based computational approach. Briefly, …
Stimulation Of Heat Shock Protein 90 Chaperone Function Through Binding Of A Novobiocin Analog Ku-32, Bhaskar K. Chatterjee, Abhilash Jayaraj, Vinay Kumar, Brian Blagg, Rachel E. Davis, B Jayaram, Shashank Deep, Tapan K. Chaudhuri
Stimulation Of Heat Shock Protein 90 Chaperone Function Through Binding Of A Novobiocin Analog Ku-32, Bhaskar K. Chatterjee, Abhilash Jayaraj, Vinay Kumar, Brian Blagg, Rachel E. Davis, B Jayaram, Shashank Deep, Tapan K. Chaudhuri
Faculty Publications
Heat shock protein 90 (Hsp90) is a eukaryotic chaperone responsible for the folding and functional activation of numerous client proteins, many of which are oncoproteins. Thus, Hsp90 inhibition has been intensely pursued, resulting in the development of many potential Hsp90 inhibitors, not all of which are well-characterized. Hsp90 inhibitors not only abrogate its chaperone functions, but also could help us gain insight into the structure-function relationship of this chaperone. Here, using biochemical and cell-based assays along with isothermal titration calorimetry, we investigate KU-32, a derivative of the Hsp90 inhibitor novobiocin (NB), for its ability to modulate Hsp90 chaperone function. Although …
Domain Rearrangement And Denaturation In Ebola Virus Protein Vp40, Rudramani Pokhrel, Pornthep Sompornpisut, Prem Chapagain, Brian Olson, Bernard Gertsman, Ras B. Pandey
Domain Rearrangement And Denaturation In Ebola Virus Protein Vp40, Rudramani Pokhrel, Pornthep Sompornpisut, Prem Chapagain, Brian Olson, Bernard Gertsman, Ras B. Pandey
Faculty Publications
The VP40 protein plays a critical role in coordinating the virion assembly, budding, and replication of the Ebola virus. Efforts have been made in recent years to understand various aspects of VP40 structure, dynamics, and function such as assembly of the protein and its roles in virus replication and penetration of the protein into the plasma membrane. A major conformational transformation is necessary for VP40 to form some of its oligomeric structures and to perform various functions. This conformational change from a compact structure with the N-terminal domain (NTD) and C-terminal domain (CTD) closely associated involves a dissociation or springing-out …
Nearly Defect-Free Dynamical Models Of Disordered Solids: The Case Of Amorphous Silicon, Raymond Atta-Fynn, Parthapratim Biswas
Nearly Defect-Free Dynamical Models Of Disordered Solids: The Case Of Amorphous Silicon, Raymond Atta-Fynn, Parthapratim Biswas
Faculty Publications
It is widely accepted in the materials modeling community that defect-free realistic networks of amorphous silicon cannot be prepared by quenching from a molten state of silicon using classical or ab initio molecular-dynamics (MD) simulations. In this work, we address this long-standing problem by producing nearly defect-free ultra-large models of amorphous silicon, consisting of up to half a million atoms, using classical MD simulations. The structural, topological, electronic, and vibrational properties of the models are presented and compared with experimental data. A comparison of the models with those obtained from using the modified Wooten-Winer-Weaire bond-switching algorithm shows that the models …
Preferential Binding Effects On Protein Structure And Dynamics Revealed By Coarse-Grained Monte Carlo Simulation, Ras B. Pandey, D.L. Jacobs, Barry L. Farmer
Preferential Binding Effects On Protein Structure And Dynamics Revealed By Coarse-Grained Monte Carlo Simulation, Ras B. Pandey, D.L. Jacobs, Barry L. Farmer
Faculty Publications
The effect of preferential binding of solute molecules within an aqueous solution on the structure and dynamics of the histone H3.1 protein is examined by a coarse-grained Monte Carlo simulation. The knowledge-based residue-residue and hydropathy-index-based residue-solvent interactions are used as input to analyze a number of local and global physical quantities as a function of the residue-solvent interaction strength (f). Results from simulations that treat the aqueous solution as a homogeneous effective solvent medium are compared to when positional fluctuations of the solute molecules are explicitly considered. While the radius of gyration (Rg) of the …
Binding Of Solvated Peptide (Eplqlkm) With A Graphene Sheet Via Simulated Coarse-Grained Approach, Somayyeh Sheikholeslami, R. B. Pandey, Nadiya Dragneva, Wely Floriano, Oleg Rubel, Stephen A. Barr, Zhifeng Kuang, Rajiv Berry, Rajesh Naik, Barry Farmer
Binding Of Solvated Peptide (Eplqlkm) With A Graphene Sheet Via Simulated Coarse-Grained Approach, Somayyeh Sheikholeslami, R. B. Pandey, Nadiya Dragneva, Wely Floriano, Oleg Rubel, Stephen A. Barr, Zhifeng Kuang, Rajiv Berry, Rajesh Naik, Barry Farmer
Faculty Publications
Binding of a solvated peptide A1 (1E 2P 3L 4Q 5L 6K 7M) with a graphene sheet is studied by a coarse-grained computer simulation involving input from three independent simulated interaction potentials in hierarchy. A number of local and global physical quantities such as energy, mobility, and binding profiles and radius of gyration of peptides are examined as a function of temperature (T). Quantitative differences (e.g., the extent of binding within a temperature range) and qualitative similarities are observed in results from three simulated potentials. Differences in variations of both local and …
Low Mach Number Fluctuating Hydrodynamics Of Diffusively Mixing Fluids, Aleksandar Donev, Andy J. Nonaka, Yifei Sun, Thomas Fai, Alejandro Garcia, John B. Bell
Low Mach Number Fluctuating Hydrodynamics Of Diffusively Mixing Fluids, Aleksandar Donev, Andy J. Nonaka, Yifei Sun, Thomas Fai, Alejandro Garcia, John B. Bell
Faculty Publications
We formulate low Mach number fluctuating hydrodynamic equations appropriate for modeling diffusive mixing in isothermal mixtures of fluids with different density and transport coefficients. These equations eliminate the fast isentropic fluctuations in pressure associated with the propagation of sound waves by replacing the equation of state with a local thermodynamic constraint. We demonstrate that the low Mach number model preserves the spatio-temporal spectrum of the slower diffusive fluctuations. We develop a strictly conservative finite-volume spatial discretization of the low Mach number fluctuating equations in both two and three dimensions. We construct several explicit Runge-Kutta temporal integrators that strictly maintain the …
Methane Adsorption On Aggregates Of Fullerenes: Site-Selective Storage Capacities And Adsorption Energies, Alexander Kaiser, Samuel Zottl, Peter Bartl, Christian Leidlmair, Andreas Mauracher, Michael Probst, Stephan Denifl, Olof Echt, Paul Scheier
Methane Adsorption On Aggregates Of Fullerenes: Site-Selective Storage Capacities And Adsorption Energies, Alexander Kaiser, Samuel Zottl, Peter Bartl, Christian Leidlmair, Andreas Mauracher, Michael Probst, Stephan Denifl, Olof Echt, Paul Scheier
Faculty Publications
Methane adsorption on positively charged aggregates of C60 is investigated by both mass spectrometry and computer simulations. Calculated adsorption energies of 118–281 meV are in the optimal range for high‐density storage of natural gas. Groove sites, dimple sites, and the first complete adsorption shells are identified experimentally and confirmed by molecular dynamics simulations, using a newly developed force field for methane–methane and fullerene–methane interaction. The effects of corrugation and curvature are discussed and compared with data for adsorption on graphite, graphene, and carbon nanotubes.
A Polarizable Reactive Force Field For Water To Enable Molecular Dynamics Simulations Of Proton Transport, Abhishek Asthana, Dean R. Wheeler
A Polarizable Reactive Force Field For Water To Enable Molecular Dynamics Simulations Of Proton Transport, Abhishek Asthana, Dean R. Wheeler
Faculty Publications
A new polarizable water model is developed for molecular dynamics (MD) simulations of the proton transport process. The interatomic potential model has three important submodels corresponding to electrostatic interactions, making and breaking of covalent bonds, and treatment of electron exchange and correlation through a van der Waals potential. A polarizable diffuse charge density function was used to describe Coulombic interactions between atoms. Most of the model parameters were obtained from ab initio data for a lone water molecule. Molecules respond realistically to their electrochemical environment by the use of coupled fluctuating charge and fluctuating dipole dynamics, which controlled the charge …
Mechanism Of Fiber Assembly: Treatment Of Aβ Peptide Aggregation With A Coarse-Grained United-Residue Force Field, Ana Rojas, Adam Liwo, Dana Browne, Harold A. Scheraga
Mechanism Of Fiber Assembly: Treatment Of Aβ Peptide Aggregation With A Coarse-Grained United-Residue Force Field, Ana Rojas, Adam Liwo, Dana Browne, Harold A. Scheraga
Faculty Publications
The growth mechanism of β-amyloid (Aβ) peptide fibrils was studied by a physics-based coarse-grained united-residue model and molecular dynamics (MD) simulations. To identify the mechanism of monomer addition to an Aβ1-40 fibril, we placed an unstructured monomer at a distance of 20 Å from a fibril template and allowed it to interact freely with the latter. The monomer was not biased towards fibril conformation by either the force field or the MD algorithm. With the use of a coarse-grained model with replica-exchange molecular dynamics, a longer timescale was accessible, making it possible to observe how the monomers probe different binding …
Mpsa Effects On Copper Electrodeposition Investigated By Molecular Dynamics Simulations, John N. Harb, Richard L. Rowley, Dean R. Wheeler, Clint G. Guymon
Mpsa Effects On Copper Electrodeposition Investigated By Molecular Dynamics Simulations, John N. Harb, Richard L. Rowley, Dean R. Wheeler, Clint G. Guymon
Faculty Publications
In superconformal filling of copper-chip interconnects, organic additives are used to fill high-aspect-ratio trenches or vias from the bottom up. In this study we report on the development of intermolecular potentials and use molecular dynamics simulation.
Mpsa Effects On Copper Electrodeposition Investigated By Molecular Dynamics Simulations, Clint G. Guymon, John N. Harb, Richard L. Rowley, Dean R. Wheeler
Mpsa Effects On Copper Electrodeposition Investigated By Molecular Dynamics Simulations, Clint G. Guymon, John N. Harb, Richard L. Rowley, Dean R. Wheeler
Faculty Publications
In superconformal filling of copper-chip interconnects, organic additives are used to fill high-aspect-ratio trenches or vias from the bottom up. In this study we report on the development of intermolecular potentials and use molecular dynamics simulations to provide insight into the molecular function of an organic additive (3-mercaptopropanesulfonic acid or MPSA) important in superconformal electrodeposition. We also investigate how the presence of sodium chloride affects the surface adsorption and surface action of MPSA as well as the charge distribution in the system. We find that NaCl addition decreases the adsorption strength of MPSA at a simulated copper surface and attenuates …
Transient Molecular Dynamics Simulations Of Viscosity For Simple Fluids, Richard L. Rowley, Jason C. Thomas
Transient Molecular Dynamics Simulations Of Viscosity For Simple Fluids, Richard L. Rowley, Jason C. Thomas
Faculty Publications
A transient molecular dynamics (TMD) method has been developed for simulation of fluid viscosity. In this method a sinusoidal velocity profile is instantaneously overlaid onto equilibrated molecular velocities, and the subsequent decay of that velocity profile is observed. The viscosity is obtained by matching in a least-squares sense the analytical solution of the corresponding momentum transport boundary-value problem to the simulated decay of the initial velocity profile. The method was benchmarked by comparing results obtained from the TMD method for a Lennard-Jones fluid with those previously obtained using equilibrium molecular dynamics (EMD) simulations. Two different constitutive models were used in …
Periodic Boundary Condition Induced Breakdown Of The Equipartition Principle And Other Kinetic Effects Of Finite Sample Size In Classical Hard-Sphere Molecular Dynamics Simulation, Randall B. Shirts, Scott R. Burt, Aaron M. Johnson
Periodic Boundary Condition Induced Breakdown Of The Equipartition Principle And Other Kinetic Effects Of Finite Sample Size In Classical Hard-Sphere Molecular Dynamics Simulation, Randall B. Shirts, Scott R. Burt, Aaron M. Johnson
Faculty Publications
We examine consequences of the non-Boltzmann nature of probability distributions for one-particle kinetic energy, momentum, and velocity for finite systems of classical hard spheres with constant total energy and nonidentical masses. By comparing two cases, reflecting walls (NVE or microcanonical ensemble) and periodic boundaries (NVEPG or molecular dynamics ensemble), we describe three consequences of the center-of-mass constraint in periodic boundary conditions: the equipartition theorem no longer holds for unequal masses, the ratio of the average relative velocity to the average velocity is increased by a factor of [N/(N–1)]^1/2, and the ratio of average collision energy to average kinetic energy is …
Stereoselectivity Of 8-Oh-Dpat Toward The Serotonin 5-Ht1a Receptor: Biochemical And Molecular Modeling Study, Joanna Dabrowska, Michal Brylinski
Stereoselectivity Of 8-Oh-Dpat Toward The Serotonin 5-Ht1a Receptor: Biochemical And Molecular Modeling Study, Joanna Dabrowska, Michal Brylinski
Faculty Publications
The great majority of pharmacological investigations of 5-HT1A receptors' reactivity has been performed using racemic 8-OH-DPAT, therefore the biochemical as well as behavioral profiles of both 8-OH-DPAT enantiomers are not circumstantiated. In the biochemical study capability of racemic 8-OH-DPAT (0.05, 0.1 mg/kg s.c.) and its counterparts R-8-OH-DPAT (0.05, 0.1 mg/kg s.c.) and S-8-OH-DPAT (0.05, 0.1 mg/kg s.c.) to influence 5-HT synthesis rate in rats' prefrontal cortex, hypothalamus, hippocampus and brainstem was evaluated by HPLC/ED technique. Biochemical results are supported by the exhaustive computational study of possible differences between R- and S-enantiomer toward the 5-HT1A receptor. A reliable 3D model of …
Effects Of Solvent Model Flexibility On Aqueous Electrolyte Behavior Between Electrodes, Richard L. Rowley, John N. Harb, Clint G. Guymon, Matthew L. Hunsaker, Douglas Henderson
Effects Of Solvent Model Flexibility On Aqueous Electrolyte Behavior Between Electrodes, Richard L. Rowley, John N. Harb, Clint G. Guymon, Matthew L. Hunsaker, Douglas Henderson
Faculty Publications
Molecular dynamics simulations have been carried out for aqueous electrolyte solutions between model electrode surfaces. The effect of solvent model flexibility on bult and double layer properties was observed for electrode surface charge densities of 0, 0.1 and 0.2 and ion concentrations of 0, 0.5 and 1 M. Two flexible models were used to isolate the effects of flexibility from the effects of a change in the condensed-phase dipole moment. Model flexibility increases the pure water self-diffusion coefficient while a larger liquid diple moment substantially decreases it. There is an increase in ion contact adsorption and counter ion affinity with …
Simplified Calculation Of The Stability Matrix For Semiclassical Propagation, Sophya Garashchuk, John C. Light
Simplified Calculation Of The Stability Matrix For Semiclassical Propagation, Sophya Garashchuk, John C. Light
Faculty Publications
We present a simple method of calculation of the stability (monodromy) matrix that enters the widely used semiclassical propagator of Herman and Kluk and almost all other semiclassical propagators. The method is based on the unitarity of classical propagation and does not involve any approximations. The number of auxiliary differential equations per trajectory scales linearly rather than quadratically with the system size. Just the first derivatives of the potential surface are needed. The method is illustrated on the collinear H[sub 3] system.
Determination Of A Methane Intermolecular Potential Model For Use In Molecular Simulations From Ab Initio Calculations, Richard L. Rowley, Tapani A. Pakkanen
Determination Of A Methane Intermolecular Potential Model For Use In Molecular Simulations From Ab Initio Calculations, Richard L. Rowley, Tapani A. Pakkanen
Faculty Publications
The possibility of obtaining an accurate site-site potential model suitable for use in molecular dynamics (MD) simulations of methane from ab initio calculations has been explored. Counterpoise-corrected (CPC), supermolecule, ab initio energies at the MP2/6-311 + G(2df,2pd) level were computed for eleven relative orientations of two methane molecules as a function of C-C separation distance. C-C, C-H, and H-H interaction parameters in a pairwise-additive, site-site potential model for rigid methane molecules were regressed from the ab initio energies, and the resultant model accurately reproduced the ab initio energies. The model suggests that C-H attractions are dominant in weakly binding the …
Integrated Computational Chemistry System For Catalysts Design, Salai Cheettu Ammal, S. Takami, M. Kubo, A. Miyamoto
Integrated Computational Chemistry System For Catalysts Design, Salai Cheettu Ammal, S. Takami, M. Kubo, A. Miyamoto
Faculty Publications
The understanding of valuable catalytic and adsorptive properties of heterogeneous catalysts at atomic and electronic levels is essential for the design of novel catalysts. Computer simulation studies can significantly contribute to provide a rational interpretation of the observed experimental results and suggest modification of new catalysts. Our recent work on the application of integrated computer simulation methods to investigate the structure and catalytic properties of solid surfaces including zeolites, transition metals and their oxides have been reviewed in this paper. We have emphasized the effectivity and applicability of integrated computer simulation system to solve the problems in a variety of …
Computer Simulations Of Branched Alkanes: The Effect Of Side Chain And Its Position On Rheological Behavior, Richard L. Rowley, Tapani A. Pakkanen, Maija Lahtela, Mikko Linnolahti
Computer Simulations Of Branched Alkanes: The Effect Of Side Chain And Its Position On Rheological Behavior, Richard L. Rowley, Tapani A. Pakkanen, Maija Lahtela, Mikko Linnolahti
Faculty Publications
Nonequilibrium molecular dynamics simulations have been performed on model fluids representing eicosane isomers in order to investigate the effect of branching and side chain position on fluid rheology. A heterogeneous, united-atom model with 20 Lennard-Jones interaction sites located at carbon centers was used to model the fluids. Vibrations and bond rotations were frozen, but torsional rotation was included. It was found that viscosity increases significantly from the n-alkane structure to a branch on carbon 2, but the movement of the branch along the carbon backbone has a smaller increasing than decreasing effect. The size of the group in a branched …
Predicting The Viscosity Of Alkanes Using Nonequilibrium Molecular Dynamics: Evaluation Of Intermolecular Potential Models, Richard L. Rowley, William Allen
Predicting The Viscosity Of Alkanes Using Nonequilibrium Molecular Dynamics: Evaluation Of Intermolecular Potential Models, Richard L. Rowley, William Allen
Faculty Publications
Nonequilibrium molecular dynamics (NEMD) viscosity simulations of branched and linear alkanes at liquid densities were performed using both united-atom (UA) and all-atom (AA) intermolecular potential models in order to study the relative efficacy of the models in predicting fluid viscosity. Both models were used in conjunction with fixed bond lengths and bond angles, but different torsional potentials were investigated. The commonly used Ryckaert—Bellemans intermolecular potential model, which accurately predicts viscosities for short straight-chain alkanes, produced values for branched and long-chain alkanes that were significantly below experimental values. Likewise, a more complex UA model that uses transferrable site potentials and is …
Molecular-Level Modeling Of The Viscoelasticity Of Crosslinked Polymers: Effect Of Time And Temperature, P. P. Simon, Harry J. Ploehn
Molecular-Level Modeling Of The Viscoelasticity Of Crosslinked Polymers: Effect Of Time And Temperature, P. P. Simon, Harry J. Ploehn
Faculty Publications
We present a new molecular-level picture of chain dynamics for describing the viscoelasticity of crosslinked polymers. The associated mathematical model consists of a time-dependent momentum balance on a representative polymer segment in the crosslinked network, plus phenomenological expressions for forces acting on the segments. These include a cohesive force that accounts for intermolecular attraction, an entropic force describing the thermodynamics governing chain conformations, and a frictional force that captures the temperature dependence of relative chain motion. We treat the case of oscillatory uniaxial deformation. Solution of the model equations in the frequency domain yields the dynamic moduli as functions of …
Note On The Number Dependence Of Nonequilibrium Molecular Dynamics Simulations Of The Viscosity Of Structured Molecules, Richard L. Rowley, James F. Ely
Note On The Number Dependence Of Nonequilibrium Molecular Dynamics Simulations Of The Viscosity Of Structured Molecules, Richard L. Rowley, James F. Ely
Faculty Publications
Nonequilibrium molecular dynamics simulations have been performed for a system of 512 four-site models representing n-butane molecules. The results are compared to simulations previously reported for 125 molecules to check a recently reported number dependence in such simulations. A small system size dependence was observed at low shear rates, but the rheological behavior is not affected. Considerably greater certainty is obtained using larger systems.
Molecular Dynamics Simulation Of Real-Fluid Mutual Diffusion Coefficients With The Lennard-Jones Potential Model, Richard L. Rowley, J. M. Stoker
Molecular Dynamics Simulation Of Real-Fluid Mutual Diffusion Coefficients With The Lennard-Jones Potential Model, Richard L. Rowley, J. M. Stoker
Faculty Publications
Mutual diffusion coefficients for selected alkanes in carbon tetrachloride were calculated using molecular dynamics and Lennard-Jones (LJ) potentials. Use of effective spherical LJ parameters is desirable when possible for two reasons: (i) computer time is saved due to the simplicity of the model and (ii) the number of parameters in the model is kept to a minimum. Results of this study indicate that mutual diffusivity is particularly sensitive to the molecular size cross parameter, σ12, and that the commonly used Lorentz–Berthelot rules are inadequate for mixtures in which the component structures differ significantly. Good agreement between simulated and experimental mutual …
Hard-Sphere Theory For Correlation Of Tracer Diffusion Of Gases And Liquids In Alkanes, Michael A. Matthews, Aydin Akgerman
Hard-Sphere Theory For Correlation Of Tracer Diffusion Of Gases And Liquids In Alkanes, Michael A. Matthews, Aydin Akgerman
Faculty Publications
No abstract provided.