pith. sign in

arxiv: 2407.15156 · v1 · pith:ELSQJGV5new · submitted 2024-07-21 · 🧮 math.NA · cs.NA

Computational and analytical studies of a new nonlocal phase-field crystal model in two dimensions

Pith reviewed 2026-05-23 23:05 UTC · model grok-4.3

classification 🧮 math.NA cs.NA
keywords nonlocal phase-field crystalstructure factorFourier spectral methodasymptotically compatiblecrystal structuresgrain boundariesphase transition
0
0 comments X

The pith

A data-driven nonlocal phase-field crystal model matches material structure factor data up to the second peak.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper presents a nonlocal phase-field crystal model whose interaction kernel is chosen by fitting to the structure factor of the material. This choice lets the model reproduce experimental structure factor values more accurately than the local phase-field crystal model or its fractional variant, reaching agreement through the second peak. The nonlocal model contains the local and fractional versions as distinct scaling limits, which shows its generality. Fourier spectral methods are introduced for discretization and are shown to converge while remaining asymptotically compatible. Two-dimensional simulations demonstrate the model's use for crystal structures and grain boundaries.

Core claim

The nonlocal phase-field crystal model incorporates a finite range of spatial nonlocal interactions through a data-driven kernel fitted to the structure factor, allowing it to account for both repulsive and attractive effects and match experimental data up to the second peak, an achievement not possible with other PFC variants. Both the local phase-field crystal and fractional phase-field crystal models are distinct scaling limits of this nonlocal model.

What carries the argument

The data-driven nonlocal kernel fitted to the structure factor, which defines the finite-range interactions and enables retention of material properties in the NPFC model.

If this is right

  • The NPFC model retains material properties better and is therefore more suitable for characterizing liquid-solid transition systems.
  • Fourier spectral discretizations of the NPFC are convergent and asymptotically compatible, making them robust across different parameter ranges.
  • Two-dimensional numerical experiments show the NPFC can simulate crystal structures and grain boundaries effectively.
  • The local and fractional PFC models arise as scaling limits, confirming that the NPFC framework is more general.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Fitting the kernel only to the structure factor may overlook higher-order correlations needed for accurate phase-transition dynamics.
  • The asymptotically compatible discretizations could support simulations that vary the interaction range continuously without reformulating the scheme.
  • The same data-driven kernel construction might improve accuracy in other nonlocal phase-field models for materials beyond crystals.
  • Testing the model against direct molecular dynamics data on grain boundary energies would provide an independent check on the fitting procedure.

Load-bearing premise

The specific functional form of the nonlocal kernel is correctly identified by fitting to the structure factor alone.

What would settle it

A calculation or experiment in which the NPFC model matches the structure factor to the second peak yet fails to reproduce observed crystal growth rates or grain boundary motion would show the fitting approach is insufficient.

Figures

Figures reproduced from arXiv: 2407.15156 by Jiang Yang, Kai Wang, Qiang Du.

Figure 1
Figure 1. Figure 1: Fit of structure factor of 36Ar. Next, we make some comparisons with XPFC models with multi-peak Gaussians. For XPFC models [6], the free energy is expressed as E(ϕ) = Z Ω  1 − ε 2 ϕ 2 − a 3 ϕ 3 + v 4 ϕ 4  − 1 2 Z Z Ω [ϕ(x)C2(∥x − x ′ ∥)ϕ(x ′ )] dx′ dx, where the pair correlation function is approximated by a combination of modulated Gaussian functions in Fourier space via Cˆ 2(k) = max(G i (k), Gi+1(k),… view at source ↗
Figure 2
Figure 2. Figure 2: Structure fitting for different materials at various temperatures. [PITH_FULL_IMAGE:figures/full_fig_p009_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Fit of structure factor of 36Ar with XPFC. 3. Properties of the NPFC and the discretization schemes To present some theoretical analysis, we assume that the operators −Lδ and −L˜ δ are all positive definite, which are reasonable assumptions that can be verified for the fitting parameters used. The NPFC equation given in (1.6) is a gradient flow of nonlocal free energy (1.3) associated with the dual space n… view at source ↗
Figure 4
Figure 4. Figure 4: (Example 4.2) Numerical evolutions of NPFC and LPFC models [PITH_FULL_IMAGE:figures/full_fig_p017_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: (Example 4.3) Snapshots of the grain boundary mismatch of θ = 11.6 ◦(top), θ = 26.3 ◦(middle) and θ = 39.4 ◦(bottom). The green pentagons and red heptagons are located at the 5|7 dislocation dipoles. We conduct two experiments in this example. The first one starts from a hexag￾onal lattice as the initial value with ϵ = 0.49, while the other one starts from a square lattice as the initial value with ϵ = 0.0… view at source ↗
Figure 6
Figure 6. Figure 6: (Example 4.4) Phase evolution for NPFC models starting from initial hexagonal lattice [PITH_FULL_IMAGE:figures/full_fig_p020_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: (Example 4.4) Phase evolution for NPFC models starting from initial square lattice. Theorem 4.3. Assume ϕ ∗ is a solution to the aforementioned conserved NPFC model (4.4) and ϕ ∗ (x) = 0 at point x = x ∗ . Then ϕ ∗ is continuous at x = x ∗ when |cδ − 1| ≥ √ ϵ; ϕ ∗ is discontinuous at x = x ∗ when |cδ − 1| < √ ϵ and ρδ +2− 2 cδ < 0 [PITH_FULL_IMAGE:figures/full_fig_p020_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: (Example 4.5) Graph of numerical solutions for various values taken by δ. studies show that the NPFC can provide much better fitting of the structure factor obtained by experiment data, thus enhancing its modeling capability. The NPFC model can be viewed as the gradient flow in the dual space of the energy space associated with the ND operator. We numerically solve NPFC models using an SAV scheme with Four… view at source ↗
read the original abstract

A nonlocal phase-field crystal (NPFC) model is presented as a nonlocal counterpart of the local phase-field crystal (LPFC) model and a special case of the structural PFC (XPFC) derived from classical field theory for crystal growth and phase transition. The NPFC incorporates a finite range of spatial nonlocal interactions that can account for both repulsive and attractive effects. The specific form is data-driven and determined by a fitting to the materials structure factor, which can be much more accurate than the LPFC and previously proposed fractional variant. In particular, it is able to match the experimental data of the structure factor up to the second peak, an achievement not possible with other PFC variants studied in the literature. Both LPFC and fractional PFC (FPFC) are also shown to be distinct scaling limits of the NPFC, which reflects the generality. The advantage of NPFC in retaining material properties suggests that it may be more suitable for characterizing liquid-solid transition systems. Moreover, we study numerical discretizations using Fourier spectral methods, which are shown to be convergent and asymptotically compatible, making them robust numerical discretizations across different parameter ranges. Numerical experiments are given in the two-dimensional case to demonstrate the effectiveness of the NPFC in simulating crystal structures and grain boundaries.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 0 minor

Summary. The manuscript introduces a nonlocal phase-field crystal (NPFC) model whose interaction kernel is determined by fitting to the material structure factor S(k). It claims this yields a match to experimental S(k) data up to the second peak, unlike LPFC or FPFC variants, while establishing LPFC and FPFC as distinct scaling limits of NPFC. Fourier spectral discretizations are shown to be convergent and asymptotically compatible, with 2D numerical experiments demonstrating crystal structures and grain boundaries.

Significance. If the S(k) fit produces demonstrably better predictions of phase-transition dynamics or material properties (e.g., elastic constants, grain-boundary energies) than LPFC/FPFC, the NPFC would represent a useful data-informed extension of existing PFC models. The scaling-limit results and asymptotically compatible discretizations are clear strengths that would remain valuable even if the superiority claim requires further support.

major comments (2)
  1. [Abstract] Abstract: the central claim that NPFC is 'more suitable for characterizing liquid-solid transition systems' because it matches experimental S(k) up to the second peak rests on a kernel fitted directly to S(k). This renders the reported improvement a consequence of the fitting step rather than an independent test; no additional validation on quantities such as radial distribution functions, elastic moduli, or grain-boundary energies is described to confirm that the S(k) match improves the nonlinear dynamics of the phase transition.
  2. [Numerical methods] Numerical discretization section: convergence and asymptotic compatibility of the Fourier spectral scheme are asserted, yet the manuscript provides neither the explicit discretization analysis, error tables, nor sensitivity tests with respect to the nonlocal kernel parameters that would allow verification of these properties across the claimed parameter ranges.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive comments, which help clarify the scope and presentation of our results. We address each major comment below and indicate the revisions planned for the next version of the manuscript.

read point-by-point responses
  1. Referee: [Abstract] Abstract: the central claim that NPFC is 'more suitable for characterizing liquid-solid transition systems' because it matches experimental S(k) up to the second peak rests on a kernel fitted directly to S(k). This renders the reported improvement a consequence of the fitting step rather than an independent test; no additional validation on quantities such as radial distribution functions, elastic moduli, or grain-boundary energies is described to confirm that the S(k) match improves the nonlinear dynamics of the phase transition.

    Authors: The referee is correct that the improved match to experimental S(k) up to the second peak follows directly from fitting the nonlocal kernel to the data. This is by design: the NPFC is formulated precisely to allow such data-driven flexibility, overcoming the structural limitations of the LPFC (quadratic dispersion) and FPFC (power-law kernel) that prevent fitting beyond the first peak. The structure factor is the central experimental observable that PFC-type models are constructed to reproduce, so the ability to match an additional peak constitutes a substantive modeling advance. The manuscript demonstrates the consequences for phase-transition dynamics through 2D simulations of crystal structures and grain boundaries. We agree, however, that explicit comparisons on derived quantities (e.g., grain-boundary energies or elastic moduli) would provide stronger independent support. We will add such quantitative comparisons in the revised manuscript. revision: yes

  2. Referee: [Numerical methods] Numerical discretization section: convergence and asymptotic compatibility of the Fourier spectral scheme are asserted, yet the manuscript provides neither the explicit discretization analysis, error tables, nor sensitivity tests with respect to the nonlocal kernel parameters that would allow verification of these properties across the claimed parameter ranges.

    Authors: The manuscript asserts convergence and asymptotic compatibility on the basis of standard Fourier spectral analysis for nonlocal integro-differential equations, together with the known theory for asymptotically compatible schemes. We acknowledge that the current text does not include explicit error tables or parameter-sensitivity studies. We will expand the numerical-methods section to include (i) a concise outline of the discretization analysis, (ii) numerical error tables for representative kernel parameters, and (iii) sensitivity tests confirming robustness across the relevant parameter regimes. revision: yes

Circularity Check

1 steps flagged

NPFC superiority in matching S(k) to second peak is by construction from data-driven fitting to that same quantity

specific steps
  1. fitted input called prediction [Abstract]
    "The specific form is data-driven and determined by a fitting to the materials structure factor, which can be much more accurate than the LPFC and previously proposed fractional variant. In particular, it is able to match the experimental data of the structure factor up to the second peak, an achievement not possible with other PFC variants studied in the literature."

    The kernel is explicitly chosen via fitting to S(k) data; the paper then claims the improved match to S(k) up to the second peak as evidence of superiority. The match is enforced by the fitting procedure itself rather than emerging as an independent result or prediction from the model equations.

full rationale

The paper's central modeling claim and evidence of advantage over LPFC/FPFC rests on the nonlocal kernel being fitted to the structure factor S(k), after which the resulting match to experimental S(k) (up to the second peak) is presented as a derived achievement. This reduces the 'prediction' or 'advantage' directly to the fitting input by construction, with no shown independent validation on dynamics, elastic properties, or higher-order correlations. LPFC/FPFC are derived as scaling limits, but that does not rescue the load-bearing S(k) claim from the fitting step.

Axiom & Free-Parameter Ledger

1 free parameters · 2 axioms · 0 invented entities

The model is introduced as a data-driven special case of the structural PFC framework; the kernel is not derived from first principles but selected to match measured structure-factor data. No new particles or forces are postulated.

free parameters (1)
  • nonlocal kernel parameters
    Chosen by fitting to experimental structure factor data; the specific values are not reported in the abstract.
axioms (2)
  • domain assumption The NPFC is a special case of the structural PFC derived from classical field theory.
    Invoked in the opening sentence of the abstract to position the new model.
  • standard math Fourier spectral methods applied to the nonlocal operator remain convergent and asymptotically compatible.
    Stated as a property of the chosen discretization without proof details in the abstract.

pith-pipeline@v0.9.0 · 5752 in / 1561 out tokens · 21862 ms · 2026-05-23T23:05:10.330047+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

61 extracted references · 61 canonical work pages

  1. [1]

    C. V. Achim, M. Karttunen, K. R. Elder, E. Granato, T. Ala-Nissila, and S. C. Ying, Phase diagram and commensurate-incommensurate transitions in the phase field crystal model with an external pinning potential, Phys. Rev. E , 74(2) (2006): 021104

  2. [2]

    Ainsworth and Z

    M. Ainsworth and Z. Mao, Phase field crystal based prediction of temperature and density dependence of elastic constants through a structural phase transition,Physical Review B., 100 (2019), 104101

  3. [3]

    Ainsworth and Z

    M. Ainsworth and Z. Mao, Fractional phase-field crystal modelling: analysis, approx- imation and pattern formation, IMA J. Appl. Math. , 85 (2020), 231–262

  4. [4]

    Aksoylu and M

    B. Aksoylu and M. L. Parks, Variational theory and domain decomposition for non- local problems, Appl. Math. Comput. , 217 (2011), 6498–6515

  5. [5]

    Andreu, J

    F. Andreu, J. M. Maz´ on, J. D. Rossi, and J. Toledo, Nonlocal diffusion Problems, Math. Surveys Monographs 165, AMS, Providence, RI , (2010)

  6. [6]

    V.Ankudinov, Structural phase-field crystal model for Lennard-Jones pair interaction potential, Modelling Simul. Mater. Sci. Eng. , 30(2022):064002. Nonlocal phase-field crystal models in two dimensions 37

  7. [7]

    Applebaum , Levy processes and stochastic calculus , Cambridge Stud

    D. Applebaum , Levy processes and stochastic calculus , Cambridge Stud. Adv. Math. , 93 (2004), Cambridge University Press, Cambridge, UK

  8. [8]

    Askari, F

    E. Askari, F. Bobaru, R. B. Lehoucq, M. L. Parks, S. A. Silling, and O. Weckner , Peridynamics for multiscale materials modeling, J. Phys. Conf. Ser. , 125 (2008), 12–78

  9. [9]

    P. W. Bates and A. Chmaj , An integrodifferential model for phase transitions: Sta- tionary solutions in higher space dimensions, J. Statist. Phys. , 95 (1999), 1119–1139

  10. [10]

    Bobaru and M

    F. Bobaru and M. Duangpanya, The peridynamic formulation for transient heat con- duction , Internat. J. Heat Mass Transfer , 53 (2010), 4047–4059

  11. [11]

    Bobaru, M

    F. Bobaru, M. Yang, L. F. Alves, S. A. Silling, E. Askari, and J. Xu, Convergence, adaptive refinement, and scaling in 1d peridynamics, Internat. J. Numer. Methods Engrg., 77 (2009), 852–877

  12. [12]

    Burch and R

    N. Burch and R. B. Lehoucq, Classical, nonlocal, and fractional diffusion equations on bounded domains, Internat. J. Multiscale Comput. Engrg. , 9 (2011), 661–674

  13. [13]

    Burkovska and M

    O. Burkovska and M. Gunzburger, On a nonlocal Cahn-Hilliard model permitting sharp interfaces, Arxiv 2004.14379, (2020)

  14. [14]

    Chen and M

    X. Chen and M. Gunzburger, Continuous and discontinuous finite element methods for a peridynamics model of mechanics, Comput. Methods Appl. Mech. Engrg. , 200 (2011), 1237–1250

  15. [15]

    Cheng and J

    M. Cheng and J. Warren, An efficient algorithm for solving the phase field crystal model, J. Comput. Phys. , 227.12 (2008), 6241–6248

  16. [16]

    Du, Nonlocal modeling, analysis and computation, CBMS-NSF regional conference series in applied mathematics, 94, (2020)

    Q. Du, Nonlocal modeling, analysis and computation, CBMS-NSF regional conference series in applied mathematics, 94, (2020)

  17. [17]

    Q. Du, M. Gunzburger, R. B. Lehoucq, and K. Zhou, Analysis and approximation of nonlocal diffusion problems with volume constraints, SIAM Rev., 56 (2012), 676–696

  18. [18]

    Q. Du, M. Gunzburger, R. B. Lehoucq, and K. Zhou, A nonlocal vector calculus, non- local volume-constrained problems, and nonlocal balance laws, Math. Models Methods Appl. Sci. , 23 (2013), 493–540

  19. [19]

    Q. Du, Y. Tao, X. Tian and J. Yang, Asymptotically compatible discretization of multidimensional nonlocal diffusion models and approximation of nonlocal Green’s functions, IMA J. Numer. Anal., 39(2) (2019), 607–625

  20. [20]

    Du and J

    Q. Du and J. Yang, Asymptotically compatible spectral approximations of nonlocal Allen-Cahn equations, SIAM J. Numer. Anal. , 54(3) (2016), 1899-1919

  21. [21]

    Du and J

    Q. Du and J. Yang, Fast and accurate implementation of Fourier spectral approxi- mations of nonlocal diffusion operators and its applications, J. Comput. Phys. , 332 (2017), 118–134

  22. [22]

    Eckhaus, Studies in non-linear stability theory , Springer Science & Business Media, 6(2012)

    W. Eckhaus, Studies in non-linear stability theory , Springer Science & Business Media, 6(2012)

  23. [23]

    O. Eder, B. Kunsch, M. Suda, E. Erdpresser and H. Stiller, The strudture factor of liquid copper at 1319 K and 1833K, J. Phys. F: Metal Phys. , 10 (1980), 183

  24. [24]

    K. R. Elder and M. Grant, Modeling elastic and plastic deformations in nonequilibrium processing using phase field crystals, Phys. Rev. E , 70(5) (2004), 051605

  25. [25]

    K. R. Elder, M. Katakowski, M. Haataja and M. Grant, Modeling elasticity in crystal growth, Phys. Rev. Lett. , 88(24) (2002), 245701

  26. [26]

    Emmrich and O

    E. Emmrich and O. Weckner, On the well-posedness of the linear peridynamic model and its convergence towards the Navier equation of linear elasticity, Commun. Math. Sci., 5 (2007), 851–864

  27. [27]

    Emmerich, H

    H. Emmerich, H. L¨ owen, R. Wittkowskib, T. Gruhna, G.I. T´ oth, G. Tegze and L. Gr´ an´ asy, Phase-field-crystal models for condensed matter dynamics on atomic length and diffusive time scales: an overview, Adv. Phys., 61 (2012), 665–743. 38 Q. Du, K. Wang, J. Yang

  28. [28]

    Fife , Some nonclassical trends in parabolic and parabolic-like evolutions, Trends in nonlinear analysis , Springer Berlin Heidelberg, (2003), 153–191

    P. Fife , Some nonclassical trends in parabolic and parabolic-like evolutions, Trends in nonlinear analysis , Springer Berlin Heidelberg, (2003), 153–191

  29. [29]

    Gomez and X

    H. Gomez and X. Nogueira, An unconditionally energy-stable method for the phase field crystal equation, Comput. Methods Appl. Mech. Engrg. , 249/252 (2012), 52–61

  30. [30]

    Greenwood, N

    M. Greenwood, N. Provatas, and J. Rottler, Free energy functionals for efficient phase field crystal modeling of structural phase transformationsPhys. Rev. Lett., 105 (2010), 045702

  31. [31]

    Z. Hu, S. Wise, C. Wang and J. Lowengrub, Stable and efficient finite-difference nonlinear-multigrid schemes for the phase-field crystal equation, J. Comput. Phys. , 228 (2009), 5323–5339

  32. [32]

    Kilic and E

    B. Kilic and E. Madenci, Coupling of peridynamic theory and the finite element method, J. Mech. Materials Structures , 5 (2010), 707–733

  33. [33]

    Y. Li, R. Slevinsky, Fast and accurate algorithms for the computation of spheri- cally symmetric nonlocal diffusion operators on lattices, J. Comput. Phys. , 397(2019), 108870

  34. [34]

    Liu and L

    J. Liu and L. Mieussens, Analysis of an asymptotic preserving scheme for linear kinetic equations in the diffusion limit, SIAM J. Numer. Anal. , 48 (2010), 1474–1491

  35. [35]

    Macek and S

    R. Macek and S. A. Silling, Peridynamics via finite element analysis, Finite Elements Analy. Design, 43 (2007), 1169–1178

  36. [36]

    Mengesha and Q

    T. Mengesha and Q. Du, Analysis of a scalar nonlocal peridynamic model with a sign changing kernel, Discrete Cont. Dyn. B , 18(5)(2013), 1415–1437

  37. [37]

    S. K. Mkhonta, K. R. Elder, and Z. F. Huang, Exploring the Complex World of Two-Dimensional Ordering with Three Modes, Phys. Rev. Lett. , 111 (2013), 035501

  38. [38]

    Palatucci, O

    G. Palatucci, O. Savin and E. Valdinoci, Peridynamic analysis of fiber-reinforced com- posite materials, J. Mech. Materials Structures , 7 (2012), 45–84

  39. [39]

    Provatas, J.A

    N. Provatas, J.A. Dantzig, B. Athreya, P. Chan, P. Stefanovic, N. Goldenfeld, K.R. El- der, Using the phase-field crystal method in the multiscale modeling of microstructure evolution, JOM, 59 (2007), 83

  40. [40]

    Yussouff, First-principles order-parameter theory of freez- ing, Phys

    TV Ramakrishnan and M. Yussouff, First-principles order-parameter theory of freez- ing, Phys. Rev. B , 19(5) (1979), 2775

  41. [41]

    Seleson, M

    P. Seleson, M. Parks, M. Gunzburger, and R. Lehoucq, Peridynamics as an upscaling of molecular dynamics, Multiscale Model. Simul. , 8 (2009), 204–227

  42. [42]

    Seymour and N

    M. Seymour and N. Provatas, Structural phase field crystal approach for model- ing graphene and other two-dimensional structures, Physical Review B. , 93 (2016), 035447

  43. [43]

    Smith and N, Provatas, Generalization of the binary structural phase field crystal model

    N. Smith and N, Provatas, Generalization of the binary structural phase field crystal model. Physical Review Materials , 1 (2017), 053407

  44. [44]

    Shen and J

    J. Shen and J. Xu, Convergence and error analysis for the scalar auxiliary variable (SAV) schemes to gradient flows, SIAM J. Numer. Anal. , 56(5) (2018), 2895–2912

  45. [45]

    J. Shen, J. Xu and J. Yang, The scalar auxiliary variable (SAV) approach for gradient flows, J. Comput. Phys. , 353 (2018), 407–416

  46. [46]

    J. Shen, J. Xu and J. Yang, A new class of efficient and robust energy stable schemes for gradient flows, SIAM Rev., 61 (2019), 474–506

  47. [47]

    Silling, Reformulation of elasticity theory for discontinuities and long-range forces, J

    S.A. Silling, Reformulation of elasticity theory for discontinuities and long-range forces, J. Mech. Phys. Solids , 48 (2000), 175–209

  48. [48]

    S. A. Silling and E. Askari, A meshfree method based on the peridynamic model of solid mechanics, Comput. Structures, 83 (2005), 1526–1535

  49. [49]

    S. A. Silling and R. B. Lehoucq, Peridynamic theory of solid mechanics, Adv. Appl. Mech., 44 (2010), 73–168

  50. [50]

    S. A. Silling, O. Weckner, E. Askari, and F. Bobaru, Crack nucleation in a peridynamic Nonlocal phase-field crystal models in two dimensions 39 solid, Internat. J. Fracture , 162 (2010), 219–227

  51. [51]

    Starodumov, V

    I. Starodumov, V. Ankudinov and I. Nizovtseva, A review of continuous modeling of periodic pattern formation with modified phase-field crystal models. The European Physical Journal Special Topics , 231 (2022), 1135–1145

  52. [52]

    Swift and P

    J. Swift and P. C. Hohenberg, Hydrodynamic fluctuations at the convective instability, Phys. Rev. A , 15(1) (1977), 319

  53. [53]

    Tian and Q

    X. Tian and Q. Du, Analysis and comparison of different approximations to nonlocal diffusion and linear peridynamic equations, SIAM J. Numer. Anal. , 51 (2013), 3458– 3482

  54. [54]

    Tian and Q

    X. Tian and Q. Du, Asymptotically compatible schemes and applications to robust discretization of nonlocal models, SIAM J. Numer. Anal. , 52 (2014), 1641–1665

  55. [55]

    van Teeffelen, R

    S. van Teeffelen, R. Backofen, A. Voigt and H. L¨ owen, Derivation of the phase-field- crystal model for colloidal solidification, Phys. Rev. E , 79(5) (2009),051404

  56. [56]

    Tuckerman and D

    L. Tuckerman and D. Barkley, Bifurcation analysis of the Eckhaus instability, Physica D: Nonlinear Phenomena , 46(1) (1990), 57–86

  57. [57]

    Wang and H

    H. Wang and H. Tian, A fast Galerkin method with efficient matrix assembly and storage for a peridynamic model, J. Comput. Phys. , 240 (2012), 49–57

  58. [58]

    Waseda and K

    Y. Waseda and K. Suzuki, Structure factor and atomic distribution in liquid metals by X-ray diffraction, Physica status solidi (b) , 49 (1972), 339–347

  59. [59]

    S. Wise, C. Wang and J. Lowengrub, An energy-stable and convergent finite-difference scheme for the phase-field crystal equation, SIAM J. Numer. Anal. , 47 (2009), 2269– 2288

  60. [60]

    Yarnell, M

    J. Yarnell, M. Katz, R. Wenzel and S. Koenig, Structure factor and radial distribution function for liquid argon at 85K, Phys. Rev. A , 7(6) (1973), 21–30

  61. [61]

    Zhou and Q

    K. Zhou and Q. Du, Mathematical and numerical analysis of linear peridynamic mod- els with nonlocal boundary conditions, SIAM J. Numer. Anal. , 48 (2010), 1759–1780