Hybrid quantum-classical approach for atomistic simulation of metallic systems

Dziedzic, Jacek; Bobrowski, Maciej

doi:10.1103/physrevb.83.224114

Cited by 7 publications

(3 citation statements)

References 40 publications

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“…Recently, ternary potentials have been developed to address the problem of chemical complexity, but they seem to be even less transferable to structures they were not fitted to, and no general consensus has been reached in the community upon their reliability. Non-uniform precision techniques such as the 'learn on the fly' (LOTF) multiscale quantum mechanical/molecular mechanical (QM/MM) scheme [16,17] appear promising, although they have not yet been extensively applied to metallic systems [18][19][20]. Augmenting this approach by learning algorithms that allow performing QM calculations only where and when they are necessary could further reduce the overall computational cost [21].…”

Section: Introductionmentioning

confidence: 99%

Modelling defects in Ni–Al with EAM and DFT calculations

Bianchini

Kermode

Vita

2016

Modelling Simul. Mater. Sci. Eng.

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We present detailed comparisons between the results of embedded atom model (EAM) and density functional theory (DFT) calculations on defected Ni alloy systems. We find that the EAM interatomic potentials reproduce low-temperature structural properties in both the γ and γ′ phases, and yield accurate atomic forces in bulk-like configurations even at temperatures as high as ∼1200 K. However, they fail to describe more complex chemical bonding, in configurations including defects such as vacancies or dislocations, for which we observe significant deviations between the EAM and DFT forces, suggesting that derived properties such as (free) energy barriers to vacancy migration and dislocation glide may also be inaccurate. Testing against full DFT calculations further reveals that these deviations have a local character, and are typically severe only up to the first or second neighbours of the defect. This suggests that a QM/MM approach can be used to accurately reproduce QM observables, fully exploiting the EAM potential efficiency in the MM zone. This approach could be easily extended to ternary systems for which developing a reliable and fully transferable EAM parameterisation would be extremely challenging e.g. Ni alloy model systems with a W or Re-containing QM zone.

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Section: Introductionmentioning

confidence: 99%

Modelling defects in Ni–Al with EAM and DFT calculations

Bianchini

Kermode

Vita

2016

Modelling Simul. Mater. Sci. Eng.

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“…Understanding the structure of liquid Cu-In alloys is also useful in investigating the properties of industrially important ternary alloys like In-Bi-Cu and In-Sb-Cu [8]. The microscopic structural aspects of liquid alloys have been investigated by ab initio molecular dynamic (AIMD) methods, Density Functional Theory (DFT) studies, Monte Carlo (MC), and Reverse Monte Carlo (RMC) simulations [12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Correlation between structures and atomic transport properties of compound forming liquid Cu-In alloys

Lalnuntluanga¹,

Lalneihpuii²,

Pachuau³

et al. 2022

Phys. Scr.

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The Lebowitz solution of the Percus-Yevick hard-sphere mixture is invoked with the square-well potential function to determine Ashcroft-Langreth type three partial correlation functions in binary Cu-In liquid alloys. These computed partial correlation functions have been employed to generate Bhatia-Thornton fluctuations in the considered melts. Using these structural parameters we investigate the temperature and composition-dependent diffusion coefficients of considered melts. The computed values of concentration-concentration fluctuations, in the long-wavelength limit and the Warren-Cowley short-range order parameter, show the formation of chemical compounds between unlike atoms in the In-rich region of Cu-In melts. We find a very good agreement between theoretically formulated and computed data of with the corresponding experimental values. Computed results of and suggest that hetero coordination is favorable over homo coordination in the investigated melts. The validity of the Stokes-Einstein relation was observed over a wide range of temperature and composition in the investigated melts. Further, a new correlation between two body pair excess entropy and the Stoke-Einstein relation has been formulated for square-well binary liquid alloys. Surface tension and compressibility as a function of In composition have been computed through microscopic structural functions of the alloys. Computed , , surface tension and ratio of mutual to intrinsic diffusion (Dm/Did) are found comparable to available simulated data. The computed values of shear viscosity are in good agreement with the experimental data. Calculated results suggest that the combination of hard sphere potential with square-well tail under mean spherical model approximation is one of the good method for determining the structures and transport coefficients of compound forming binary liquid alloys.

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“…In fact the QM/MM techniques are classified according to the method of creating this interface with variants that are used in chemistry and biochemistry, [3][4][5] and materials. 6,7 In cases where the quantum and classical systems are not connected through chemical bonds, the interaction between the quantum and classical parts includes only nonbonded terms (Coulomb, exchange repulsion, and dispersion). case is usually referred to as "electrostatic embedding" as the quantum system is embedded in an environment of fixed charges.…”

Section: Introductionmentioning

confidence: 99%

Electrostatic embedding in large-scale first principles quantum mechanical calculations on biomolecules

Fox

Pittock

Fox

et al. 2011

The Journal of Chemical Physics

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Biomolecular simulations with atomistic detail are often required to describe interactions with chemical accuracy for applications such as the calculation of free energies of binding or chemical reactions in enzymes. Force fields are typically used for this task but these rely on extensive parameterisation which in cases can lead to limited accuracy and transferability, for example for ligands with unusual functional groups. These limitations can be overcome with first principles calculations with methods such as density functional theory (DFT) but at a much higher computational cost. The use of electrostatic embedding can significantly reduce this cost by representing a portion of the simulated system in terms of highly localised charge distributions. These classical charge distributions are electrostatically coupled with the quantum system and represent the effect of the environment in which the quantum system is embedded. In this paper we describe and evaluate such an embedding scheme in which the polarisation of the electronic density by the embedding charges occurs self-consistently during the calculation of the density. We have implemented this scheme in a linear-scaling DFT program as our aim is to treat with DFT entire biomolecules (such as proteins) and large portions of the solvent. We test this approach in the calculation of interaction energies of ligands with biomolecules and solvent and investigate under what conditions these can be obtained with the same level of accuracy as when the entire system is described by DFT, for a variety of neutral and charged species.

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Hybrid quantum-classical approach for atomistic simulation of metallic systems

Cited by 7 publications

References 40 publications

Modelling defects in Ni–Al with EAM and DFT calculations

Modelling defects in Ni–Al with EAM and DFT calculations

Correlation between structures and atomic transport properties of compound forming liquid Cu-In alloys

Electrostatic embedding in large-scale first principles quantum mechanical calculations on biomolecules

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