Article
Engineering, Mechanical
I. A. Bryukhanov
Summary: In molecular dynamics simulations of shock compression and spall fracture in [111] copper single crystals with pre-existing dislocations, it is found that the increase in dislocation density behind the shock wave is quadratic and independent of the initial dislocation density. Pre-existing dislocations almost do not affect the spall strength but significantly slow down the spall process, resulting in a more ductile fracture.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Materials Science, Multidisciplinary
Jo Caulkins, Carlisle Fauver, Sara Adibi, Justin Wilkerson
Summary: A suite of molecular dynamics simulations is used to study the effect of grain boundary misorientation on spall strength in pure BCC tantalum. The results show that the homogeneous extension method requires fewer atoms and computational costs compared to the piston/flyer impact method for similar spall strength predictions.
Article
Biochemistry & Molecular Biology
Andrea Amadei, Andrea Ciccioli, Antonello Filippi, Caterina Fraschetti, Massimiliano Aschi
Summary: A theoretical-computational procedure based on the quasi-Gaussian entropy theory and molecular dynamics simulations is proposed. It can construct an analytical model of the most relevant thermodynamic properties within a wide temperature range by automatically sampling the entire conformational repertoire of highly flexible systems. The method's reliability mainly depends on the quality of the force field used in the simulations and the ability to distinguish between semi-classical and quantum degrees of freedom in a physically coherent way.
Article
Engineering, Chemical
Joachim Eichenlaub, Karol Baran, Maciej Smiechowski, Adam Kloskowski
Summary: Understanding the mechanism of carbon dioxide absorption in ionic liquids is crucial for their effective use in industrial flue gas treatment. This study calculated the Fractional Free Volume (FFV) of 73 ILs and used a quantitative structure-property relationship study to predict it, but the validation parameters were not satisfactory. In the second part, the importance of FFV in CO2 absorption was assessed by creating two models to predict Henry's Law Constant, which showed that incorporating FFV significantly improved the predictive accuracy of the models and allowed for the determination of subtle molecular interactions.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Engineering, Mechanical
Victor V. Pogorelko, Alexander E. Mayer
Summary: Molecular dynamics (MD) simulations were used to study the fracture mechanisms of iron under uniaxial and isotropic tension. The results showed that uniaxial tension led to the formation of a complex dislocation structure, reducing the pore formation threshold and spall strength. However, increasing the temperature suppressed the increase in dislocation density, resulting in an increase in spall strength. Preliminary compression of the material created a defect structure, which reduced the spall strength during tension.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Chemistry, Physical
Daniele Coslovich, Robert L. Jack, Joris Paret
Summary: This study uses unsupervised learning methods to characterize the disordered microscopic structure of supercooled liquids and glasses. Dimensionality reduction is performed on smooth structural descriptors, and the ability of the method to capture the essential structural features of glassy binary mixtures is assessed. The results indicate that some mixtures have well-defined locally favored structures and are reflected in bimodal distributions of structural variables identified through dimensionality reduction.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Jiacheng Rong, Pengzhe Zhu, Yimeng Xu
Summary: This paper investigates the spallation process of metallic glass under different velocities by using molecular dynamics simulation and the piston method. The results show that higher loading velocities lead to higher material strain rates and temperatures, reducing the spall strength. The analysis reveals that icosahedral clusters are greatly reduced in spallation, and higher strain rates result in more voids and a larger spall region, with a change in the fracture surface characteristics.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Hao Zhang, Hui Peng, Xiao-Yang Pei, Jian-Ying Wu, Ping Li, Tie-Gang Tang, Ling-Cang Cai, Yi Li, Hai Liu
Summary: In this work, a unified phase field theory for two coupled fracture types is proposed. This theory considers the coupling behavior between different fracture types and is consistent with the single fracture type theory when one type of fracture is suppressed. A double phase-field model for coupled spall and adiabatic shear banding is realized with this unified phase field theory, which can be used to predict the potential failures in ductile metals under dynamic loading. The entire damage and fracture evolution, including damage evolution, crack expansion, and fragmentation, can be captured with this modeling framework.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Biochemistry & Molecular Biology
Irina A. Kutlubulatova, Maria S. Grigoryeva, Veronika A. Dimitreva, Stanislav Yu. Lukashenko, Andrey P. Kanavin, Viktor Yu. Timoshenko, Dmitry S. Ivanov
Summary: The production of non-toxic and homogeneous colloidal solutions of nanoparticles (NPs) is crucial for biomedical applications. Pulsed laser ablation in liquids (PLAL) is a powerful and efficient method for generating chemically pure silicon nanoparticles. However, controlling the final characteristics of the particles and achieving a narrow size distribution in the colloidal solutions is challenging. Fragmentation of NPs obtained through laser irradiation can be utilized, but the resulting NP characteristics depend on laser irradiation parameters and material properties. Therefore, understanding the mechanism of NP fragmentation is important for generating colloidal solutions with desired properties.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Physical
B. P. Prajwal, James M. Blackwell, Patrick Theofanis, Fernando A. Escobedo
Summary: This work introduces a computational framework to study the molecular inhomogeneities in chemically amplified photoresists. Molecular dynamics simulations were used to investigate the effect of ionic and steric interactions on the dispersibility of photoacid generators (PAGs) in polymer medium. The results show that the dispersibility of PAGs varies depending on their ionic nature and the polymer used.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Physical
Fangfang Chen, Xiaoen Wang, Michel Armand, Maria Forsyth
Summary: Polymer electrolytes are important for future high-energy-density batteries. In this study, a polymeric ionic liquid was used as a polymer solvent to achieve high ionic conductivity and metal ion transference number simultaneously for sodium and potassium electrolytes. Experimental results confirmed the predicted fast ion transport in the polymer-in-salt environment, and demonstrated good ionic conductivity and stable cycling performance. This research offers an alternative strategy for designing high-performance sustainable battery chemistries.
Article
Mechanics
J. Lira-Escobedo, J. R. Velez-Cordero, Pedro E. Ramirez-Gonzalez
Summary: This study investigates the dynamical heterogeneities in glass-forming liquids during cooling processes using a theoretical framework. The findings suggest that slow cooling rates lead to the relaxation of the system towards a homogeneous local density equilibrium state, while fast cooling rates result in dynamically arrested density-fluctuations and the formation of permanent spatial heterogeneities even in the presence of density gradients.
Article
Chemistry, Physical
Vinicius Piccoli, Leandro Martinez
Summary: Ionic liquids (ILs) are widely used in biotechnological applications for their interactions with proteins. In this study, we investigated the solvation of different ubiquitin folding states in IL aqueous solutions and found that ILs preferentially solvate protein structures and are considered denaturants. The exposure of low-polarity residues during protein denaturation allows favorable interactions with ILs, stabilizing the protein core.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Multidisciplinary
Dong-Dong Jiang, Peng-Yu Chen, Pei Wang, An-Min He
Summary: This study investigates the effects of Cu nanoparticle inclusion on the dynamic responses of single crystal Al during shockwave loading and spallation processes through molecular dynamics simulations. The inclusion of Cu in Al-Cu nanocomposite results in a lower spall strength compared to ideal single crystal Al at specific impact velocities, due to the formation of a regular stacking fault structure. Additionally, the damage evolution process shows that voids tend to nucleate and grow along the inclusion interface when the piston velocity is within a certain range.
Article
Materials Science, Multidisciplinary
Leah Granger, Muh-Jang Chen, Donald Brenner, Mohammed Zikry
Summary: Atomistic molecular dynamics and microstructural dislocation density-based crystalline plasticity framework were used to simulate the behavior of a copper-nickel interface under high strain rates. Both methods showed similar qualitative behavior, indicating that the nanoscale behavior can represent microstructural behavior.
Article
Materials Science, Multidisciplinary
Elena M. Kirova, Genri E. Norman, Vasily V. Pisarev
COMPUTATIONAL MATERIALS SCIENCE
(2020)
Article
Materials Science, Multidisciplinary
Alexander Antropov, Vladimir Stegailov
JOURNAL OF NUCLEAR MATERIALS
(2020)
Article
Physics, Condensed Matter
E. M. Kirova, V. V. Pisarev
Summary: The study simulated the nucleation and growth of crystalline nuclei in a molybdenum film cooled between two amorphous walls, comparing the results for wall-confined and wall-free systems. It found two mechanisms of crystal growth in both free and confined systems, with the dominant mechanism shifting from attachment to coalescence as the cooling rate increases. The presence of amorphous walls did not affect the geometric characteristics of long-lived crystal clusters, but the system confined between walls showed higher glass-forming ability.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Chemistry, Physical
V Negodin, Y. Polyachenko, D. Fleita, V Pisarev, G. Norman
Summary: The equilibrium and metastable states of the Lennard-Jones vapor, liquid, and crystal near phase transition points were studied, with transitions modeled using molecular dynamics. A four-point correlation function and its correlation coefficient were used to qualitatively detect collective motions of atoms in these states, revealing singularities at the transition from equilibrium to metastable states, which are discussed as precursors of nucleation.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Computer Science, Hardware & Architecture
Nikolay Kondratyuk, Vsevolod Nikolskiy, Daniil Pavlov, Vladimir Stegailov
Summary: This study compares the performance of molecular dynamics calculations using LAMMPS, GROMACS, and OpenMM MD packages on different GPU backends. It shows that porting the CUDA backend of LAMMPS to ROCm HIP can provide considerable benefits for AMD GPUs compared to the OpenCL backend.
INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS
(2021)
Article
Nanoscience & Nanotechnology
Alexander Vasiliev, Leonid Matveev, Alexander Mikhaylov, Artem Mitrofanov, Yuri Obukhov, Nikita Orekhov, Alexander Osadchy, Vladimir Stegailov
Summary: Using density functional theory, this study investigates the properties of excited short-living electron quantum levels of positively charged C-60 fullerenes numerically. The research verifies the existence of volume-localized states and calculates physical parameters of all electronic states, focusing on highly charged fullerene ions. Results show ionization potentials, photoionization cross-sections, and varying lifetimes of excited states with volume-localized levels having longer lifetimes compared to surface-localized states.
JOURNAL OF NANOMATERIALS
(2021)
Article
Thermodynamics
Nikolay D. Kondratyuk, Vasily V. Pisarev
Summary: In this paper, molecular dynamics methods were used to predict the pressure-viscosity dependencies of a model lubricant at three different temperatures, showing agreement with experimental data and observing faster-than-exponential dependence behavior.
FLUID PHASE EQUILIBRIA
(2021)
Article
Materials Science, Multidisciplinary
Alexander Antropov, Vladimir Stegailov
Summary: In this study, molecular dynamics modeling revealed a new diffusion mechanism for xenon nanobubbles in UO2, which could potentially explain the contradictory data on bubble diffusion and fission gas release rate in UO2.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Chemistry, Physical
E. Tararushkin, V. V. Pisarev, A. G. Kalinichev
Summary: This study uses a new modification of the ClayFF force field to investigate the impact of metal-O-H interactions on the crystal structure and surface hydrogen bond strength, as well as the adsorption behavior of ions and mobility of water molecules. The new version of the force field significantly improves the accuracy of reproducing the elastic characteristics of the crystal.
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Physics, Condensed Matter
M. Shutikova, V. V. Stegailov
Summary: In this paper, point defect formation energies for the cubic phase of magnetite are calculated using the DFT + U method, and the electronic structure calculations and atomic relaxation peculiarities are discussed. The results show that only the cubic phase model with a small band gap and charge disproportionation gives an adequate point defect formation energy.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
Ilya D. Fedorov, Vladimir V. Stegailov
Summary: The transition of warm dense fluid hydrogen from an insulator to a conducting state has been a topic of active research with inconsistent results. This study used the ROKS method to simulate the dynamics of dense hydrogen after thermal excitation, and the Wannier localization method to analyze the exciton dynamics. The model suggests that the dissociation of electron-hole pairs is a key mechanism for the transition, explaining various stages and resolving discrepancies between experimental studies.
Article
Materials Science, Multidisciplinary
D. A. Kolotinskii, V. S. Nikolaev, V. V. Stegailov, A. V. Timofeev
Summary: The Point Defect Model (PDM) has been adapted for the application of lead-bismuth coolants, involving modifications in electrochemical reactions and the model of electrostatic potential distribution in the oxide film. The proposed PDM_PB model is optimized using experimental data for T91 grade steel and demonstrates applicability for lead and lead-bismuth coolants, which is critical for next-generation fast-neutron reactors.
Article
Materials Science, Multidisciplinary
Alexander Antropov, Vladimir Stegailov
Summary: The influence of helium pressure on the diffusion mechanisms of He-filled nanobubbles in fcc Al is investigated using classical molecular dynamics. It is found that at pressures below 20 kbar, gas suppresses self-diffusion by affecting the concentration of adatoms. However, at higher pressures, bubble diffusion coefficients increase due to the emission of self-interstitial atoms. The formation of dislocation loops around the bubble leads to a significant drop in the bubble diffusion coefficient at higher gas pressures. The effect of surface self-diffusion suppression cannot explain the experimental data, while the formation of dislocation loops can.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Nikita A. Fominykh, Vsevolod P. Nikolskiy, Vladimir V. Stegailov
Summary: This paper investigates the interaction between a liquid metal coolant containing dissolved iron and oxygen and an oxide film with a wustite structure using molecular dynamics modeling and thermodynamic calculations. The influence of the coolant on the chemical potentials of solvated Fe-O is examined. These findings contribute to bridging the gap between multiscale models and ab initio calculations of atomistic models.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Physics, Multidisciplinary
I. D. Fedorov, V. V. Stegailov
Summary: This study focuses on the transition from the molecular state to the atomic state in warm dense hydrogen fluid, emphasizing the importance of nonequilibrium nonadiabatic processes in this transition.
