An adaptive template method for analyzing crystal structures and defects in molecular dynamics simulations of high-rate deformations

Sapozhnikov, F.A.; Ionov, G.V.; Dremov, V. V.

doi:10.1134/s1990793108020115

Cited by 18 publications

(9 citation statements)

References 7 publications

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“…Analysis of the structural changes showed that the release of the stresses took place due to formation of twins. Results of structure recognition with the Adaptive Template Analysis (ATA) [16] show that the twins form tube-like structure oriented along [111] direction (see Fig. 7).…”

Section: Large Scale Cmd Simulationsmentioning

confidence: 99%

MD modeling of screw dislocation influence upon initiation and mechanism of BCC-HCP polymorphous transition in iron

Dremov

Ionov

Sapozhnikov

et al. 2015

EPJ Web of Conferences

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Abstract. The present work is devoted to classical molecular dynamics investigation into microscopic mechanisms of the bcchcp transition in iron. The interatomic potential of EAM type used in the calculations was tested for the capability to reproduce ab initio data on energy evolution along the bcc-hcp transformation path (Burgers deformation + shuffle) and then used in the large-scale MD simulations. The large-scale simulations included constant volume deformation along the Burgers path to study the origin and nature of the plasticity, hydrostatic volume compression of defect free samples above the bcc to hcp transition threshold to observe the formation of new phase embryos, and the volume compression of samples containing screw dislocations to study the effect of the dislocations on the probability of the new phase critical embryo formation. The volume compression demonstrated high level of metastability. The transition starts at pressure much higher than the equilibrium one. Dislocations strongly affect the probability of the critical embryo formation and significantly reduce the onset pressure of transition. The dislocations affect also the resulting structure of the samples upon the transition. The formation of layered structure is typical for the samples containing the dislocations. The results of the simulations were compared with the in-situ experimental data on the mechanism of the bcc-hcp transition in iron.

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Section: Large Scale Cmd Simulationsmentioning

confidence: 99%

MD modeling of screw dislocation influence upon initiation and mechanism of BCC-HCP polymorphous transition in iron

Dremov

Ionov

Sapozhnikov

et al. 2015

EPJ Web of Conferences

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“…The problem was resolved with the method of Adaptive Template Analysis (ATA) [16] which proved to perform very well. The method was developed at RFNC-VNIITF.…”

Section: Simulation Of Nanocluster Structures At P =mentioning

confidence: 99%

Molecular dynamics modelling of nanocarbon cluster properties under conditions close to HE detonation

Derbenev

Chizhkova

Sapozhnikov

et al. 2010

EPJ Web of Conferences

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Abstract. We use molecular dynamics for modelling properties of carbon nanoclusters.The size of modelled carbon nanoclusters is below 5 nm, which is typical of detonation diamond nanoclusters. We have found their structural changes at P = 0 to be as follows: Diamond → Diamond core + GL-surface → sandwich-type graphite → Graphite-like liquid. In smaller clusters the transformations start at a lower temperature. Adaptive Template Analysis (ATA) was used to determine the structures. We studied evaporation properties at temperatures above 5000 K. For clusters of several thousands of atoms, the simple dependence k vap ∼ e −T 0 /T /N 1/3 (T 0 is constant) is quite good. It has been found out that densities of saturated vapour for clusters containing from 4000 to 8000 atoms are very close at T = 5000 K. The structure of nanoclusters was studied at nonzero pressures set by an argon environment. Calculated results suggest that the patterns for different temperatures are qualitatively similar for three pressures under study (20, 25 and 30 GPa). At T = 1000-1500 K, the initial diamond core is preserved and a thin disordered GL layer is present on the surface. At T = 2000-5000 K, graphite grains form in the sample and a thin layer of liquid is present on its surface. The sample is amorphous at 5500 K and 6000 K. The prevalence of the graphite phase at these pressures seems to come from the absence of long-range interaction in REBO-2002.

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“…Then, it compares the extracted clusters with a reference crystal phase (Li 2 Si 2 O 5 for example), which is expected to form in the glass. A similar approach, known as the Adaptive Template Method, has been applied to identify crystal lattice types (FCC, BCC and HPC) in hard sphere systems 39 . In our algorithm, a similar idea with the Adaptive Template Method was combined with our original Cluster code 18 , which enables us to investigate more complicated crystals with multiple species in multicomponent glasses.…”

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confidence: 99%

Disclosing crystal nucleation mechanism in lithium disilicate glass through molecular dynamics simulations and free-energy calculations

Lodesani

Menziani

Maeda³

et al. 2020

Sci Rep

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Unraveling detailed mechanism of crystal nucleation from amorphous materials is challenging for both experimental and theoretical approaches. In this study, we have examined two methods to understand the initial stage of crystal precipitation from lithium disilicate glasses using molecular dynamics simulations. One of the methods is a modified exploring method to find structurally similar crystalline clusters in the glass models, enabling us to find three different embryos, such as Li2Si2O5 (LS2), Li2SiO3 (LS) and Li3PO4 (LP), in the 33Li2O·66SiO2·1P2O5 glass (LS2P1), in which P2O5 is added as a nucleating agent. Interestingly, LS2 and LP crystals were found inside the LS2P1 glass while LS crystal appeared on the glass surface, which agrees with experimental observations. The other method is free energy calculation using a subnano-scale spherical crystal embedded in the glass model. This method, which we called Free-Energy Seeding Method (FESM), allows us to evaluate free energy change as a function of crystal radius and to identify critical size of the crystal precipitation. The free energy profiles for LS and LS2 crystal nuclei in the LS2 glass models possess maximum energy at a critical radius as expected by classical nucleation theory. Furthermore, the critical radius and the energy barrier height agree well with recent experimental investigation, proving the applicability of this method to design glass–ceramics by atomistic modeling.

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An adaptive template method for analyzing crystal structures and defects in molecular dynamics simulations of high-rate deformations

Cited by 18 publications

References 7 publications

MD modeling of screw dislocation influence upon initiation and mechanism of BCC-HCP polymorphous transition in iron

MD modeling of screw dislocation influence upon initiation and mechanism of BCC-HCP polymorphous transition in iron

Molecular dynamics modelling of nanocarbon cluster properties under conditions close to HE detonation

Disclosing crystal nucleation mechanism in lithium disilicate glass through molecular dynamics simulations and free-energy calculations

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