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REVIEW 4 major objections 5 minor 44 references

Entropy-driven electron density and effective model Hamiltonian for boron systems

T0 review · 4 major / 5 minor · reviewed 2026-08-11 · deepseek-v4-flash

Pith's one-line read The paper claims that a parameter-free bonding free energy minimized under the octet rule predicts electron density and relative stability across boranes, boron clusters, and borophene.

desk verdict Max-entropy heuristic dressed up as a Hamiltonian; useful as a screening descriptor, not as a predictive energy model. read the letter →

arxiv 2412.18172 v1 pith:L6XXHJQ5 submitted 2024-12-24 cond-mat.mtrl-sci

classification cond-mat.mtrl-sci
keywords bondingfreeenergyelectrondensityoctetrulemaximumentropyprincipleboronclustersborophenegrandcanonicalensembleboraneisomers
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

The paper tries to show that a parameter-free statistical model can decide which boron structures are stable without fitting any parameter to first-principles data. The model distributes valence electrons among two-center B–B and three-center B–B–B bonds so as to minimize a bonding free energy, subject only to the octet rule on every boron atom and the duplet rule on hydrogen. Because all bonds are treated as energetically equal, the minimum is reached by spreading electrons as evenly as possible—maximizing bonding entropy—and this single principle reproduces electron densities from density functional theory. The authors apply it to borane isomers, hydrogen diffusion pathways, closo-borane charge states, size-selected boron clusters, and borophene vacancy patterns, including the prediction that vacancy concentration $\eta=1/6$ borophenes are stabilized by long-range periodicity. If correct, the model offers a chemically transparent screening criterion for boron-based structures, from molecules to two-dimensional sheets.

What carries the argument

The machinery is a grand-canonical partition function over electron occupations of the candidate bonds. For a fixed structure, the number of two-center B–B bonds and three-center B–B–B bonds is fixed by a distance cutoff of 1.65–1.92 Å, and each bond is assigned an occupation number while all bond energies are set to zero. The model Hamiltonian is the resulting free energy $F_b = (N_{\mathrm{ele}} k_B T_0/\log N_{\mathrm{ele}})\sum_i p_i \log p_i$, where $p_i$ is the fraction of electrons in bond $i$. Minimizing $F_b$ under octet and duplet constraints makes the electron distribution as uniform as the constraints allow; this is the maximum-bonding-entropy principle. The same $F_b$, evaluated at its minimum, is then used as an energy-ordering criterion for isomers, diffusion intermediates, charge states, and periodic vacancy arrangements.

What would settle it

A reader could take any octet-satisfying boron structure family, compute DFT formation energies for all isomers, and check whether the minimum-BFE isomer is always the DFT minimum; a single counterexample—for instance a short-period $\eta=1/6$ borophene that DFT finds more stable than the long-period forms—would falsify the model's ranking claim.

Watch

Extended reading notes

Core claim

The paper's central claim is that the bonding free energy $$F_b = \frac{N_{\mathrm{ele}} k_B T_0}{\log N_{\mathrm{ele}}}\sum_{i} p_i \log p_i,$$ with $p_i$ the fraction of valence electrons in bond $i$ and $N_{\mathrm{ele}}$ the total valence electrons, is a valid effective Hamiltonian for boron systems once every atom is forced to obey the octet rule. All bonds are assigned equal energy, so minimizing $F_b$ is equivalent to maximizing the bonding entropy $S=-N_{\mathrm{ele}} k_B \sum_i p_i \log p_i$; the ground-state electron density is the most uniform distribution compatible with local octets. The paper argues that this maximum-entropy density matches DFT densities for molecules such as $B_6H_{10}$ and $B_{36}$, that the minimized $F_b$ correlates linearly with DFT formation energies across isomer sets and vacancy patterns, and that it correctly selects the doubly charged $B_{12}H_{12}^{2-}$ as especially stable. It also predicts that borophene with one-sixth hexagonal vacancies becomes more stable as the vacancy pattern repeats with longer periodicity.

Load-bearing premise

The model assumes that every bond included by the distance cutoff is energetically identical, so the only thing deciding stability is how evenly electrons can be spread out while satisfying octets; if some bonds are intrinsically stronger or weaker, the predicted winner can change.

Editorial extensions

If this is right

  • For borane isomers such as $B_5H_7$, the minimum-BFE ranking reproduces DFT energy ordering, so the model can be used as a fast prefilter before explicit quantum calculations.
  • The hydrogen diffusion path in $B_8H_{12}$ obtained by sliding a hydrogen atom over boron sites has the same barrier shape as the CI-NEB reference, locating the bridge-site transition state as the maximum.
  • For closo-boranes, the model's per-electron free energy correctly gives the dianion $B_{12}H_{12}^{2-}$ as the most stable charge state, matching the second-energy-difference criterion.
  • Across boron clusters, the most stable form at each size is the one with largest bonding entropy (cage for $B_{38}$ and $B_{40}$, triple-ring for $B_{42}$, bilayer for $B_{54}$ and $B_{63}$), making entropy a structural-selection rule.
  • For borophene, higher-entropy vacancy distributions are more stable, and at vacancy concentration $\eta=1/6$, longer-period supercells have lower $F_b$ and lower DFT formation energy than shorter-period cells.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If the equal-bond assumption is the main limitation, a natural extension is to let each bond carry a small environment-dependent energy, for example from bond length or coordination, while keeping the entropy functional; the model would then interpolate between pure Lewis structures and maximum delocalization.
  • The same maximum-bonding-entropy construction may transfer to other electron-deficient main-group systems, such as aluminum or gallium clusters, where the octet and duplet constraints would need replacement by the appropriate valence-shell counts.
  • Because BFE assigns fractional bond occupancies, it could be used to seed or regularize machine-learned interatomic potentials with physically meaningful electron-density descriptors, reducing the data needed for boron-structure screening.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 5 minor

Summary. The paper proposes a 'bonding free energy' (BFE) model for boron systems, in which valence electrons are allocated among two-center and three-center bonds so as to minimize F = N_ele k_B T0 / log N_ele * sum_i p_i log p_i subject to octet and duplet constraints on every atom. The model is claimed to be parameter-free and to reproduce first-principles electron densities and total energies for boranes, all-boron clusters, and borophene, and to rank isomer energies, hydrogen diffusion pathways, optimal closo-borane charges, and borophene vacancy stabilities, including the assertion that 1/6-vacancy borophenes become more stable with long-range periodicity.

Significance. If correct, a parameter-free model that predicts electron densities and structural stability of boron allotropes would be a valuable contribution, and the paper contains a large body of comparisons with DFT results. The electron-density maps for individual molecules and clusters are visually compelling, and the attempt to connect maximum-entropy reasoning with chemical bonding is thought-provoking. However, the central claim that BFE is an effective model Hamiltonian that 'accurately predicts total energies' is not supported by the model construction, because all bond energies are set to zero and the model reduces to entropy maximization. The paper is transparent about at least one ranking failure (S4 borophene), which further limits the strength of the stability claims. The usefulness of the model as a heuristic for electron-density distribution is plausible, but the total-energy and structure-prediction claims are not established.

major comments (4)
  1. [II, Eq. (5)] Equation (5) as printed contains a sign inconsistency: the first equality reads F = -k_B T log Z - k_B T sum_i alpha_i d log Z / d alpha_i, but the correct grand-canonical Helmholtz free energy is F = -k_B T log Z + k_B T sum_i alpha_i d log Z / d alpha_i (since n_i = -d log Z/d alpha_i and mu_i = -alpha_i k_B T). The printed second line follows only after this sign is corrected. The final expression Eq. (8) can be recovered after the correction, so this is a derivation error that must be fixed; as printed, Eq. (5) does not follow from the preceding line.
  2. [II, Eqs. (1)-(10)] Setting all bond energies E_i to zero in Eq. (1) eliminates any bond-strength, bond-length, or local-environment term from the model Hamiltonian. With E_i = 0, Eq. (10) becomes F = N_ele k_B T0 / log N_ele * sum_i p_i log p_i, which is proportional to minus the Shannon entropy of the occupation probabilities. Minimizing BFE is therefore equivalent to maximizing bonding entropy under hard octet/duplet constraints. This is a maximum-entropy inference scheme, not an energetic Hamiltonian: two isomers with identical bond graphs and identical octet constraints are assigned exactly the same BFE regardless of their DFT relative energies, and the 1.65-1.92 Å bond-length cutoff is a sensitive free parameter that can reorder predictions. The claim that the model 'accurately predicts total energies' is not established by the construction.
  3. [III.D, Fig. 5(c)] The text states that 'the BFE model failed to accurately predict that the energy of S4 in Figure 5(c) is the lowest' and then claims it 'is still able to identify the S4 structure as having the lowest energy within the same supercell.' This is a direct admission that the model's top-ranked structure is not the DFT ground state for a central borophene case. The manuscript needs to state precisely which comparisons fail and to quantify the error; as written, this undercuts the paper's general claim that BFE reliably ranks isomers.
  4. [III.B, Fig. 3(c)] The prediction that B12H12 is most stable as the dianion is presented as a successful model outcome, but the octet rule is already imposed as a hard constraint on every atom, and the dianion is the charge state in which this constraint can be satisfied by the available bonding network. The compensating charge introduced for non-octet borophenes in III.D is an additional, system-dependent assumption. The paper should separate consequences of the input constraints from genuinely new predictions.
minor comments (5)
  1. [Throughout] The term 'parameter-free' is used throughout, but Eq. (10) contains the undetermined constant T0, and the bond network depends on the 1.65-1.92 Å cutoff; please specify how T0 is chosen or state that it is an arbitrary energy scale that cancels in rankings.
  2. [III.A, Fig. 2(a)] The text refers to 'the lower right corner of Figure 2(a)' when describing the DFT electron density; earlier the same figure is described with 'bottom left corner' for S*; please verify all figure-region callouts.
  3. [II, after Eq. (10)] The phrase 'k_B T functions as the coefficient to ensure that BFE is an extensive quantity' is confusing; since T = T0 / log N_ele, the factor N_ele k_B T0 / log N_ele makes F scale as N_ele only if sum_i p_i log p_i is of order -log N_ele, which should be stated explicitly.
  4. [Conclusions] The sentence 'The origin of borophene's polymorphism is linked to the reduction of bonding entropy through electron compensation' appears to reverse the earlier statement that greater bonding entropy enhances stability; please clarify which quantity increases or decreases in the compensation picture.
  5. [References] Reference [20] is an arXiv preprint (He et al., arXiv:2412.13588); please update to the published version if available.

Circularity Check

1 steps flagged · score 4.0 of 10

BFE reduces to negative entropy by construction, making the core 'entropy-driven stability' claim definitional; DFT benchmarks keep the practical rankings non-circular.

  1. self definitional [Section II, Eqs. (8)-(10); Section III.A]
    "we regard Ei for all bonds as equal, which means that the electron can be equally allocated to each bond and is set to zero for convenience. ... subsequently, the bonding free energy (BFE) can be expressed by: F = NelekBT ∑ pi log pi, (8) and the bonding entropy is defined by ... S = −NelekB ∑ pi log pi. (9)"

    Because every Ei is set to zero, Eq. (8)/(10) is F = NelekBT0/logNele ∑ p_i log p_i, while Eq. (9) gives S = -NelekB ∑ p_i log p_i. Thus F = -(T0/(kB log Nele)) S exactly. Minimizing BFE and maximizing bonding entropy are the same operation, so the paper's statement that 'the BFE exhibits a linear correlation with Sb, reaching its minimum when the bonding entropy is maximized' and the title's 'entropy-driven' claim are identities, not physical derivations. The Hamiltonian contains no bond-strength, bond-length, or environment energy beyond the connectivity graph (1.65-1.92 Å cutoff) and hard octet/duplet constraints. Therefore 'stability is entropy-driven' is true by construction.

full rationale

The central thermodynamic identity of the BFE model is self-definitional: with all bond energies set to zero, the free energy in Eq. (8)/(10) is exactly proportional to the negative of the bonding entropy defined in Eq. (9). Consequently, the paper's claims that boron stability is 'entropy-driven' and that the minimum BFE corresponds to maximum bonding entropy are true by construction rather than being independent physical derivations. This is the one genuine circular step identified. It affects the explanatory framing and the sense in which BFE is called a 'model Hamiltonian,' but it does not by itself invalidate the practical predictive comparisons, because the paper evaluates isomer rankings (Fig. 3a), hydrogen diffusion paths (Fig. 3b), vacancy-position stabilities (Fig. 4b), and borophene vacancy-distribution trends (Fig. 5a,b) against first-principles DFT results. Those DFT comparisons are external benchmarks and are not used to fit any parameter of the model. The optimal closo-borane charge and the long-period borophene stability are outputs of the constrained entropy optimization, not fitted to the benchmark energies, so they are not circular in the sense of a fitted input being renamed as a prediction. The self-citations [13,20,40-42] provide the generalized octet-rule framework and structural generation tools, but no load-bearing uniqueness theorem is imported from the authors' prior work; the model is stated self-contained. A sign inconsistency appears in the first line of the printed Eq. (5), but that is a correctness concern rather than a circularity reduction, so it does not contribute to the circularity score. Overall, a score of 4 is appropriate: one definitional circularity in the central 'entropy-driven' claim, while the practical structural predictions retain independent empirical content.

Assumptions & free parameters 3 free parameters · 7 assumptions · 3 invented entities

All inputs are the octet and duplet rules, the bond-length cutoff, and the entropy functional; the only physics in the model is the combinatorial tendency toward uniform electron sharing. The free-parameter count is small but the model is not parameter-free in the strong sense because T0, the bond-length cutoff, and the compensating charge are modeling choices.

free parameters (3)
  • Equivalent standard temperature T0
    Introduced in Eq. 10 via T = T0 / log N_ele to make the BFE extensive. Never derived or fixed; cancels in rankings within a fixed electron count but sets the scale when comparing systems with different N_ele.
  • Bond-length cutoff window = 1.65-1.92 angstroms
    Determines which atom pairs are 2c-2e bonds and which triples are 3c-2e bonds; taken from prior structural studies (Refs. 21 and 22) and applied uniformly to all structures.
  • Compensating charge for non-octet borophenes
    Ad hoc device used to extend the octet rule to vacancy concentrations other than one-ninth; the amount and physical mechanism are not specified in the main text, with details deferred to the Supplemental Material.
assumptions (7)
  • domain assumption Each boron atom obeys the octet rule and each hydrogen atom the duplet rule as hard constraints on electron allocation.
    Invoked in Section III.A and used to define the feasible set of electron distributions; the model does not allow violations.
  • ad hoc to paper All bond energies E_i are equal and set to zero, so the only contribution to the free energy is the entropy term.
    Section II, Eq. 1: 'we regard E_i for all bonds as equal... set to zero for convenience.' This removes any enthalpy difference between 2c-2e and 3c-2e bonds.
  • ad hoc to paper The statistical weight of an electron allocation is the multinomial coefficient C = N_ele!/(n_1!...n_Nbond!), and the partition function equals (sum e^{-alpha_i})^{N_ele}.
    Section II, Eqs. 2-4. The initial definition of Z (Eq. 1) lacks this degeneracy; it is inserted to match the multinomial expansion.
  • ad hoc to paper The ground state is the state of minimum BFE under the octet constraints.
    Section II, end: 'minimal BFE corresponds to the ground state of a system.' This is the model's variational principle.
  • ad hoc to paper The equivalent temperature scales as T = T0 / log N_ele to make BFE extensive.
    Eq. 10: the log N_ele denominator is introduced to cancel the N log N scaling of the bare entropy; no physical derivation is given.
  • ad hoc to paper Borophene with vacancy concentration other than one-ninth must receive a compensating charge.
    Section III.D: 'the additional electron should be compensated into the borophene.' The compensation is not observed or measured.
  • domain assumption B-H and B-H-B bonds are fully occupied, and only B-B and B-B-B bonds participate in resonance.
    Section I: 'we assume full occupation of B-H and B-H-B bonds, as hydrogen atoms follow the duplet rule.' This reduces the degrees of freedom for boranes.
invented entities (3)
  • Bonding free energy (BFE)
    purpose: A scalar functional F = N_ele k_B T sum p_i log p_i used to rank structural stability and to define the optimal electron density.
    The BFE is not a measured or independently derived thermodynamic quantity; it is a maximum-entropy functional whose temperature scale is chosen ad hoc.
  • Bonding entropy S_b
    purpose: The Shannon entropy of the electron probability distribution over bonds, claimed to drive structural stability.
    Defined by Eq. 9 as -N_ele k_B sum p_i log p_i; the claim that maximizing it stabilizes structures is a consequence of the model's definition rather than an independent empirical finding.
  • Compensating charge for non-octet borophenes
    purpose: Extra electrons added to boron monolayers whose vacancy concentration does not satisfy the octet rule, to allow the BFE model to be applied.
    No experimental or DFT evidence for a distinct compensating charge is presented in the main text; it is introduced to patch the model.

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Pith. "Pith review of Entropy-driven electron density and effective model Hamiltonian for boron systems." pith.science (2026). https://pith.science/paper/L6XXHJQ5

@misc{pith2026241218172,
  author       = {Pith},
  title        = {Pith review of: Entropy-driven electron density and effective model Hamiltonian for boron systems},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/L6XXHJQ5}},
  note         = {Machine review of arXiv:2412.18172}
}
read the original abstract

The unique electron deficiency of boron makes it challenging to determine the stable structures, leading to a wide variety of forms. In this work, we introduce a statistical model based on grand canonical ensemble theory that incorporates the octet rule to determine electron density in boron systems. This parameter-free model, referred to as the bonding free energy (BFE) model, aligns well with first-principles calculations and accurately predicts total energies. For borane clusters, the model successfully predicts isomer energies, hydrogen diffusion pathways, and optimal charge quantity for closo-boranes. In all-boron clusters, the absence of B-H bond constraints enables increased electron delocalization and flexibility. The BFE model systematically explains the geometric structures and chemical bonding in boron clusters, revealing variations in electron density that clarify their structural diversity. For borophene, the BFE model predicts that hexagonal vacancy distributions are influenced by bonding entropy, with uniform electron density enhancing stability. Notably, our model predicts borophenes with a vacancy concentration of 1 6 to exhibit increased stability with long-range periodicity. Therefore, the BFE model serves as a practical criterion for structure prediction, providing essential insights into the stability and physical properties of boron-based systems.

Figures

Figures reproduced from arXiv: 2412.18172 by the authors.

Figure 1
Figure 1. FIG. 1. (a) Current popular theories of understanding chemi [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. FIG. 2. (a) The electron allocation model for borane, three [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3. (a) The energy scatter plot of B [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
Figures from the paper (2 more)
Figure 4
Figure 4. Figure 4: FIG. 4. (a) The electron density of B [PITH_FULL_IMAGE:figures/full_fig_p006_4.png]
Figure 5
Figure 5. Figure 5: FIG. 5. (a) The energy scatter plot of borophene with var [PITH_FULL_IMAGE:figures/full_fig_p007_5.png]

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Works this paper leans on

44 extracted references · 42 canonical work pages

  1. [1]

    E. A. Carter, Challenges in modeling materials properties without experimental input, Science 321, 800 (2008)

  2. [2]

    Bannwarth, S

    C. Bannwarth, S. Ehlert, and S. Grimme, Gfn2-xtb—an accurate and broadly parametrized self-consistent tight- binding quantum chemical method with multipole elec- trostatics and density-dependent dispersion contribu- tions, J. Chem. Theory Comput. 15, 1652 (2019)

  3. [3]

    X. Shao, L. Paetow, M. E. Tuckerman, and M. Pavanello, Machine learning electronic structure methods based on the one-electron reduced density matrix, Nat. Commun. 14, 6281 (2023)

  4. [4]

    Hohenberg and W

    P. Hohenberg and W. Kohn, Inhomogeneous electron gas, Phys. Rev. 136, B864 (1964)

  5. [5]

    Entropy-driven electron density and effective model Hamiltonian for boron systems

    captures many aspects of chemical bonding, offering a practical framework for understanding molecular struc- ture. To build on the electron-pair model, Langmuir [6] and Kossel [7] introduced the octet rule, which states that main-group elements in the second period tend to gain, lose, or share electrons to achieve a complete octet in their outermost energ...

  6. [6]

    Langmuir, The octet theory of valence and its appli- cations with special reference to organic nitrogen com- pounds, J

    I. Langmuir, The octet theory of valence and its appli- cations with special reference to organic nitrogen com- pounds, J. Am. Chem. Soc. 42, 274 (1920)

  7. [7]

    G. N. Lewis, The atom and the molecule., J. Am. Chem. Soc. 38, 762 (1916)

  8. [8]

    H. C. Longuet-Higgins, The structures of electron- deficient molecules, Q. Rev. Chem. Soc. 11, 121 (1957)

Show all 44 references
  1. [9]

    Kossel, ¨Uber molek¨ ulbildung als frage des atombaus, Ann

    W. Kossel, ¨Uber molek¨ ulbildung als frage des atombaus, Ann. Phys. 354, 229 (1916)

  2. [10]

    O. T. Unke, S. Chmiela, H. E. Sauceda, M. Gastegger, I. Poltavsky, K. T. Sch¨ utt, A. Tkatchenko, and K.-R. M¨ uller, Machine learning force fields, Chem. Rev. 121, 10142 (2021)

  3. [11]

    W. J. Hehre, R. Ditchfield, L. Radom, and J. A. Pople, Molecular orbital theory of the electronic structure of organic compounds. v. molecular theory of bond separa- tion, J. Am. Chem. Soc. 92, 4796 (1970)

  4. [12]

    Hedberg and V

    K. Hedberg and V. Schomaker, A reinvestigation of the structures of diborane and ethane by electron diffrac- tion1,2, J. Am. Chem. Soc. 73, 1482 (1951)

  5. [13]

    Fedik, R

    N. Fedik, R. Zubatyuk, M. Kulichenko, N. Lubbers, J. S. Smith, B. Nebgen, R. Messerly, Y. W. Li, A. I. Boldyrev, K. Barros, O. Isayev, and S. Tretiak, Extending ma- chine learning beyond interatomic potentials for predict- ing molecular properties, Nat. Rev. Chem. 6, 653 (2022)

  6. [14]

    Osorio, Chapter 1 - describing chemical bonding in ex- otic systems through adndp analysis, in Atomic Clusters with Unusual Structure, Bonding and Reactivity, edited by P

    E. Osorio, Chapter 1 - describing chemical bonding in ex- otic systems through adndp analysis, in Atomic Clusters with Unusual Structure, Bonding and Reactivity, edited by P. K. Chattaraj, S. Pan, and G. Merino (Elsevier,

  7. [15]

    S. Xu, C. He, Y. Zhao, X. Yang, and H. Xu, Generalized octet rule with fractional occupancies for boron, J. Am. Chem. Soc. 145, 25003 (2023)

  8. [16]

    V. L. Deringer, C. J. Pickard, and G. Cs´ anyi, Data-driven learning of total and local energies in elemental boron, Phys. Rev. Lett. 120, 156001 (2018)

  9. [17]

    L. Qiu, X. Zhang, X. Kong, I. Mitchell, T. Yan, S. Y. Kim, B. I. Yakobson, and F. Ding, Theory of sigma bond resonance in flat boron materials, Nat. Commun. 14, 1804 (2023)

  10. [18]

    M. H. Lee, Ergodic theory, infinite products, and long time behavior in hermitian models, Phys. Rev. Lett. 87, 250601 (2001)

  11. [19]

    W. H. Eberhardt, J. Crawford, Bryce, and W. N. Lip- scomb, The Valence Structure of the Boron Hydrides, J. Chem. Phys. 22, 989 (2004)

  12. [20]

    He, S.-G

    C.-C. He, S.-G. Xu, J. Zeng, W. Huang, Y. Yao, Y.-J. Zhao, and H. Xu, A parameter-free statistical model for two-dimensional carbon nanostructures (2024), arXiv:2412.13588 [cond-mat.mes-hall]

  13. [21]

    Aghion, D

    E. Aghion, D. A. Kessler, and E. Barkai, From non-normalizable boltzmann-gibbs statistics to infinite- ergodic theory, Phys. Rev. Lett. 122, 010601 (2019)

  14. [22]

    Shoji, T

    Y. Shoji, T. Matsuo, D. Hashizume, M. J. Gutmann, H. Fueno, K. Tanaka, and K. Tamao, Boron–boron σ- bond formation by two-electron reduction of a h-bridged dimer of monoborane, J. Am. Chem. Soc. 133, 11058 (2011)

  15. [24]

    Henkelman, B

    G. Henkelman, B. P. Uberuaga, and H. J´ onsson, A climb- ing image nudged elastic band method for finding saddle points and minimum energy paths, J. Chem. Phys. 113, 9901 (2000)

  16. [25]

    See Supplemental Material at [URL will be inserted by publisher], for additional information about the compu- tational methods, derivation of bonding free energ model, resonance coefficient calculations, and the details for solv- ing borane, boron cluster and borophene by BFE model

  17. [26]

    W. H. Knoth, H. C. Miller, J. C. Sauer, J. H. Balthis, Y. T. Chia, and E. L. Muetterties, Chemistry of boranes. ix. halogenation of b10h10-2 and b12h12-2, Inorg. Chem. 3, 159 (1964)

  18. [27]

    J. A. Wunderlich and W. N. Lipscomb, Structure of B12H12 −2 ion, J. Am. Chem. Soc. 82, 4427 (1960)

  19. [28]

    Rohdenburg, M

    M. Rohdenburg, M. Mayer, M. Grellmann, C. Jenne, T. Borrmann, F. Kleemiss, V. A. Azov, K. R. Asmis, S. Grabowsky, and J. Warneke, Superelectrophilic behav- ior of an anion demonstrated by the spontaneous binding of noble gases to B 12Cl11 −, Angew. Chem. Int. Ed. 56, 7980 (2017)

  20. [29]

    Plesek, Potential applications of the boron cluster com- pounds, Chem

    J. Plesek, Potential applications of the boron cluster com- pounds, Chem. Rev. 92, 269 (1992)

  21. [30]

    Bhattacharyya, I

    P. Bhattacharyya, I. Boustani, and A. Shukla, Why does a b12h12 icosahedron need two electrons to be stable: A first-principles electron-correlated investigation of b12hn (n = 6, 12) clusters, J. Phys. Chem. A125, 10734 (2021)

  22. [31]

    A. H. Soloway, W. Tjarks, B. A. Barnum, F.-G. Rong, R. F. Barth, I. M. Codogni, and J. G. Wilson, The chem- istry of neutron capture therapy. (chem. rev. 1998, 98,

  23. [32]

    Z. A. Piazza, H.-S. Hu, W.-L. Li, Y.-F. Zhao, J. Li, and L.-S. Wang, Planar hexagonal b36 as a potential basis for extended single-atom layer boron sheets, Nat. Commun. 5, 3113 (2014)

  24. [33]

    Tang and S

    H. Tang and S. Ismail-Beigi, Novel precursors for boron nanotubes: The competition of two-center and three- center bonding in boron sheets, Phys. Rev. Lett. 99, 115501 (2007)

  25. [34]

    P. v. R. Schleyer, K. Najafian, and A. M. Mebel, The large closo-borane dianions, bnhn2 (n = 13-17) are aro- matic, why are they unknown?, Inorg. Chem. 37, 6765 (1998)

  26. [35]

    X. Wu, J. Dai, Y. Zhao, Z. Zhuo, J. Yang, and X. C. Zeng, Two-dimensional boron monolayer sheets, ACS Nano 6, 7443 (2012)

  27. [36]

    J. Lv, Y. Wang, L. Zhu, and Y. Ma, B38: an all-boron fullerene analogue, Nanoscale 6, 11692 (2014)

  28. [37]

    X. Yang, Y. Ding, and J. Ni, Ab initio prediction of sta- ble boron sheets and boron nanotubes: Structure, stabil- ity, and electronic properties, Phys. Rev. B 77, 041402 9 (2008)

  29. [38]

    At the same time, other types of boron 6 FIG

    and B63 [39]). At the same time, other types of boron 6 FIG. 4. (a) The electron density of B 36 and the decomposed Kekul´ e structures. (b) The energy predicted by the BFE model and DFT for B36 with one vacancy and B56 with two vacancies. (c) The evolution prediction of diffe...

  30. [39]

    J. Chen, R. Liao, L. Sai, J. Zhao, and X. Wu, B63: The most stable bilayer structure with dual aromaticity, J. Phys. Chem. Lett. 15, 4167 (2024)

  31. [40]

    Zhai, Y.-F

    H.-J. Zhai, Y.-F. Zhao, W.-L. Li, Q. Chen, H. Bai, H.-S. Hu, Z. A. Piazza, W.-J. Tian, H.-G. Lu, Y.-B. Wu, Y.- W. Mu, G.-F. Wei, Z.-P. Liu, J. Li, S.-D. Li, and L.-S. Wang, Observation of an all-boron fullerene, Nat. Chem. 6, 727 (2014)

  32. [41]

    Pei, Y.-Y

    L. Pei, Y.-Y. Ma, M. Yan, M. Zhang, R.-N. Yuan, Q. Chen, W.-Y. Zan, Y.-W. Mu, and S.-D. Li, Bilayer B54, B 60, and B 62 clusters in a universal structural pat- tern, Eur. J. Inorg. Chem. 2020, 3296 (2020)

  33. [42]

    Xu, C.-C

    S.-G. Xu, C.-C. He, Y.-J. Zhao, H. Xu, and X.-B. Yang, Unconventional line defects engineering in two- dimensional boron monolayers, Phys. Rev. Mater. 5, 044003 (2021)

  34. [43]

    He, J.-H

    C.-C. He, J.-H. Liao, S.-B. Qiu, Y.-J. Zhao, and X.- B. Yang, Biased screening for multi-component materi- als with structures of alloy generation and recognition (sagar), Comput. Mater. Sci. 193, 110386 (2021)

  35. [44]

    Xu, X.-T

    S.-G. Xu, X.-T. Li, Y.-J. Zhao, J.-H. Liao, H. Xu, and X.-B. Yang, An electron compensation mechanism for the polymorphism of boron monolayers, Nanoscale 10, 13410 (2018)

  36. [1515]

    published on the web may 20, 1998), Chem. Rev. 98, 2389 (1998)

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