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arxiv: 2606.06006 · v1 · pith:43LE5SP5new · submitted 2026-06-04 · ⚛️ physics.atm-clus

Influence of DFT Functionals on Low-Energy Electron Scattering Cross Sections of Nitric Oxide

Ashutosh Yadav , Felipe Fantuzzi , Nigel J. Mason , Bobby Antony This is my paper

Pith reviewed 2026-06-27 22:59 UTC · model grok-4.3

classification ⚛️ physics.atm-clus
keywords nitric oxideDFT functionalselectron scatteringR-matrixcross sectionsresonancestarget propertieslow-energy collisions
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The pith

Different DFT functionals alter nitric oxide's low-energy electron scattering resonances by changing its target electronic properties.

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

The paper tests how four DFT functionals and several basis sets affect computed properties of the NO molecule, including bond length, dipole moment, ionisation potential and polarisability. These properties are then used to build target models for R-matrix calculations of electron scattering cross sections between 0.1 and 20 eV. The total cross sections display resonance features whose positions and heights vary with the choice of functional, most noticeably around 0.8-1.0 eV and in a sharper structure near 1.8 eV. Differential cross sections show smaller but visible angular dependence at selected energies. The work identifies one functional-basis combination that produces results closest to experiment and proposes it as a practical route for future NO scattering models.

Core claim

The authors establish that the DFT functional and basis set used to describe the NO target directly influence the low-energy electron-scattering observables obtained from R-matrix calculations, with the largest effects appearing in the resonance structures of the total cross sections.

What carries the argument

R-matrix scattering calculations performed on electronic target models generated by different DFT functionals, which translate variations in molecular properties into changes in resonance positions and cross-section magnitudes.

If this is right

  • Resonance positions in the total cross section shift from 1.74 eV to 1.82 eV depending on the functional.
  • The broad peak near 0.8-1.0 eV exhibits the strongest dependence on the target description.
  • Differential cross sections display modest functional sensitivity, clearest at 7.5 and 10 eV.
  • ωB97X-D3 geometry optimisation with aug-cc-pVTZ followed by aug-cc-pVQZ property calculation is supported as a reliable protocol.

Where Pith is reading between the lines

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

  • The same DFT-sensitivity pattern may appear in scattering calculations for other atmospheric diatomic molecules.
  • Selecting functionals by how well they reproduce resonance locations could improve agreement with experiment across a wider energy range.
  • The protocol could be tested by predicting cross sections at energies above 20 eV and checking against new measurements.

Load-bearing premise

That the observed differences in scattering cross sections are caused mainly by variations in the DFT-generated target properties rather than by other fixed elements of the R-matrix setup.

What would settle it

High-resolution experimental measurement of the position and width of the resonance feature near 1 eV, compared directly against the calculated values obtained from each functional.

Figures

Figures reproduced from arXiv: 2606.06006 by Ashutosh Yadav, Bobby Antony, Felipe Fantuzzi, Nigel J. Mason.

Figure 1
Figure 1. Figure 1: Calculated equilibrium bond lengths of NO as a function of basis set for different [PITH_FULL_IMAGE:figures/full_fig_p009_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Calculated dipole moments of NO as a function of basis set for different density [PITH_FULL_IMAGE:figures/full_fig_p010_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Calculated ionisation potentials of NO as a function of basis set for different [PITH_FULL_IMAGE:figures/full_fig_p011_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Calculated polarisabilities of NO as a function of basis set for different density [PITH_FULL_IMAGE:figures/full_fig_p012_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Total electron-scattering cross sections of NO calculated using the R-matrix [PITH_FULL_IMAGE:figures/full_fig_p013_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Differential electron-scattering cross sections of NO calculated using the R [PITH_FULL_IMAGE:figures/full_fig_p016_6.png] view at source ↗
read the original abstract

Nitric oxide (NO) is important in biological, atmospheric, plasma, industrial, and astrophysical environments, where reliable electron-collision data support modelling charged-particle interactions with matter. Its well-known experimental properties make it suitable for assessing how the target electronic-structure description affects low-energy electron scattering calculations. In this work, NO properties were evaluated using B3LYP, M06-2X, PBE0, and $\omega$B97X-D3, with basis sets ranging from minimal to quadruple-zeta quality. Bond length, dipole moment, ionisation potential, and polarisability were compared with experiment to assess the sensitivity of the target description to the functional and basis set. The aug-cc-pVQZ basis set was then used to generate target models for ab initio R-matrix calculations over 0.1--20 eV. The total cross sections show low-energy resonance features, with the strongest functional dependence around the broad peak near 0.8--1.0 eV. A sharper, higher-energy structure is also observed below 2 eV, shifting from 1.74 to 1.82 eV depending on the functional. Differential cross sections show modest functional sensitivity, with more noticeable angular differences at 7.5 and 10 eV. These results show that the DFT functional and basis set affect the target properties, with the resulting target description influencing low-energy electron-scattering observables of NO. The comparison supports $\omega$B97X-D3/aug-cc-pVTZ geometry optimisation followed by aug-cc-pVQZ target-property calculations as a practical protocol for R-matrix modelling of NO.

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

1 major / 2 minor

Summary. The manuscript performs a systematic comparison of four DFT functionals (B3LYP, M06-2X, PBE0, ωB97X-D3) and multiple basis sets for computing NO target properties (bond length, dipole moment, ionization potential, polarizability). These targets are then used in fixed-setup ab initio R-matrix calculations to generate total and differential electron-scattering cross sections from 0.1–20 eV. Resonance positions shift with functional (broad feature 0.8–1.0 eV; sharp feature 1.74–1.82 eV), and the authors recommend ωB97X-D3/aug-cc-pVTZ geometry optimization followed by aug-cc-pVQZ property calculations as a practical protocol based on closest agreement of target properties with experiment.

Significance. If the reported sensitivity holds, the work supplies concrete, actionable guidance for choosing DFT protocols when constructing R-matrix targets for NO, a molecule relevant to atmospheric, plasma, and astrophysical modeling. The approach of holding the scattering calculation fixed while swapping only the target description isolates the effect of the electronic-structure method and yields falsifiable predictions for resonance locations that can be tested against future experiments.

major comments (1)
  1. [Results (scattering cross sections)] The central recommendation rests on target-property agreement with experiment rather than on direct validation of the resulting cross sections against measured scattering data. A quantitative statement of how much the observed 0.08 eV shift in the sharp resonance improves or worsens agreement with existing experimental total cross sections would strengthen the claim that the protocol is practically useful for scattering applications.
minor comments (2)
  1. [Abstract] The abstract states that the aug-cc-pVQZ basis set was used for the R-matrix targets, yet the recommended protocol specifies aug-cc-pVTZ for geometry optimization; a brief clarification of whether single-point property calculations at the larger basis were performed on the VTZ geometries would remove ambiguity.
  2. [Figures/Tables] Table or figure captions listing the exact resonance peak positions (in eV) for each functional would make the reported 0.8–1.0 eV and 1.74–1.82 eV ranges easier to compare quantitatively.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the positive assessment and the constructive suggestion. We address the major comment below.

read point-by-point responses

  1. Referee: [Results (scattering cross sections)] The central recommendation rests on target-property agreement with experiment rather than on direct validation of the resulting cross sections against measured scattering data. A quantitative statement of how much the observed 0.08 eV shift in the sharp resonance improves or worsens agreement with existing experimental total cross sections would strengthen the claim that the protocol is practically useful for scattering applications.

    Authors: We agree that a direct quantitative comparison of the computed total cross sections against experimental scattering data would provide stronger support for the practical utility of the recommended protocol. The manuscript isolates the effect of the target description by holding the R-matrix setup fixed and demonstrates that functional choice shifts resonance positions by up to 0.08 eV; however, it does not include a side-by-side metric (e.g., mean absolute deviation or integrated cross-section difference) versus measured total cross sections for each functional. Because the experimental total cross sections in the 1–2 eV region are themselves broad and carry their own uncertainties, the small shift is expected to produce only modest changes in agreement. In the revised manuscript we will add a concise quantitative statement comparing the computed resonance locations and the resulting total cross sections (near 1.8 eV) to the available experimental data sets, thereby addressing the referee’s point directly. revision: yes

Circularity Check

0 steps flagged

No significant circularity identified

full rationale

The paper performs independent DFT calculations for each functional/basis combination to obtain target properties (bond length, dipole, IP, polarisability), then inserts those fixed values into an otherwise unchanged R-matrix scattering calculation. Differences in resonance positions and cross sections are reported as direct consequences of the input target variation, with the final protocol recommendation resting on external experimental agreement rather than any internal fit or self-definition. No equations reduce outputs to fitted parameters defined by the inputs, no load-bearing self-citations appear, and no ansatz or uniqueness claim is smuggled in. This is a standard sensitivity study whose central inference remains independent of its own outputs.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The paper relies on standard DFT approximations and the R-matrix method without introducing new fitted parameters or postulated entities; the main inputs are the choice of four common functionals and standard basis sets.

axioms (1)
  • domain assumption DFT functionals provide sufficiently accurate target electronic properties for low-energy electron scattering calculations on NO.
    The study treats the DFT outputs as the variable input to R-matrix without independent validation of the functionals' fundamental accuracy for resonance states.

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Reference graph

Works this paper leans on

36 extracted references

  1. [1]

    Toward reliable density functional methods without adjustable parameters: The PBE0 model

    Adamo, C., Barone, V., 1999. Toward reliable density functional methods without adjustable parameters: The PBE0 model. The Journal of Chem- ical Physics 110, 6158–6170

    1999

  2. [2]

    Biomolecular Damage In- duced by Ionizing Radiation: The Direct and Indirect Effects of Low- Energy Electrons on DNA

    Alizadeh, E., Orlando, T.M., Sanche, L., 2015. Biomolecular Damage In- duced by Ionizing Radiation: The Direct and Indirect Effects of Low- Energy Electrons on DNA. Annual Review of Physical Chemistry 66, 379–398

    2015

  3. [3]

    Improved electron-molecule scattering calcu- lations with the relativistic optical-potential method

    Arya, S., Antony, B., 2026. Improved electron-molecule scattering calcu- lations with the relativistic optical-potential method. RSC Advances 16, 13548–13558

    2026

  4. [4]

    Self-Interaction Error in Den- sity Functional Theory: An Appraisal

    Bao, J.L., Gagliardi, L., Truhlar, D.G., 2018. Self-Interaction Error in Den- sity Functional Theory: An Appraisal. The Journal of Physical Chemistry Letters 9, 2353–2358

    2018

  5. [5]

    Global ob- servations of nitric oxide in the thermosphere

    Barth, C.A., Mankoff, K.D., Bailey, S.M., Solomon, S.C., 2003. Global ob- servations of nitric oxide in the thermosphere. Journal of Geophysical Research: Space Physics 108

    2003

  6. [6]

    Density‐functional thermochemistry

    Becke, A.D., 1993. Density‐functional thermochemistry. iii. the role of exact exchange. The Journal of Chemical Physics 98, 5648–5652

    1993

  7. [7]

    Gas discharge plasmas and their applications

    Bogaerts, A., Neyts, E., Gijbels, R., van der Mullen, J., 2002. Gas discharge plasmas and their applications. Spectrochimica Acta Part B: Atomic Spec- troscopy 57, 609–658

    2002

  8. [8]

    Electron scattering and transport in biofuels, biomolecules and biomass fragments

    Brunger, M.J., 2017. Electron scattering and transport in biofuels, biomolecules and biomass fragments. International Reviews in Physical Chemistry 36, 333–376. 17

    2017

  9. [9]

    Electron collisions in atmospheres

    Campbell, L., Brunger, M., 2016. Electron collisions in atmospheres. Inter- national Reviews in Physical Chemistry 35, 297–351

    2016

  10. [10]

    Multiscale Perspectives on Solid-Phase Astrochemistry: Laboratory, Computation, and Open Questions

    Dickers, M.D., Mifsud, D.V., Mason, N.J., Fantuzzi, F., 2025. Multiscale Perspectives on Solid-Phase Astrochemistry: Laboratory, Computation, and Open Questions. Space Science Reviews 221, 106

    2025

  11. [11]

    Assessment of the Perdew–Burke– Ernzerhof exchange-correlation functional

    Ernzerhof, M., Scuseria, G.E., 1999. Assessment of the Perdew–Burke– Ernzerhof exchange-correlation functional. The Journal of Chemical Physics 110, 5029–5036

    1999

  12. [12]

    New forms of asymptotic expansions for wavefunctions of charged-particle scattering

    Gailitis, M., 1976. New forms of asymptotic expansions for wavefunctions of charged-particle scattering. Journal of Physics B: Atomic and Molecular Physics 9, 843

    1976

  13. [13]

    Chapter one - chemistry of nitric oxide and related species, in: Poole, R.K

    Hughes, M.N., 2008. Chapter one - chemistry of nitric oxide and related species, in: Poole, R.K. (Ed.), Globins and Other Nitric Oxide-Reactive

    2008

  14. [14]

    Comparative DFT study for molecular geome- tries and spectra of methyl pheophorbides-a: test of M06-2X and two other functionals

    Huh, D.S., Choe, S.J., 2010. Comparative DFT study for molecular geome- tries and spectra of methyl pheophorbides-a: test of M06-2X and two other functionals. Journal of Porphyrins and Phthalocyanines 14, 592–604

    2010

  15. [15]

    Cross sections for electron collisions with nitric oxide

    Itikawa, Y., 2016. Cross sections for electron collisions with nitric oxide. Journal of Physical and Chemical Reference Data 45, 033106

    2016

  16. [16]

    The performance of Dun- ning, Jensen, and Karlsruhe basis sets on computing relative energies and geometries

    Kirschner, K.N., Reith, D., Heiden, W., 2020. The performance of Dun- ning, Jensen, and Karlsruhe basis sets on computing relative energies and geometries. Soft Materials 18, 200–214

    2020

  17. [17]

    A sensitive search for nitric oxide in the lower atmospheres of Venus and Mars: Detection on Venus and upper limit for Mars

    Krasnopolsky, V.A., 2006. A sensitive search for nitric oxide in the lower atmospheres of Venus and Mars: Detection on Venus and upper limit for Mars. Icarus 182, 80–91

    2006

  18. [18]

    Long-Range Corrected Hy- brid Density Functionals with Improved Dispersion Corrections

    Lin, Y.S., Li, G.D., Mao, S.P., Chai, J.D., 2013. Long-Range Corrected Hy- brid Density Functionals with Improved Dispersion Corrections. Journal of Chemical Theory and Computation 9, 263–272

    2013

  19. [19]

    Microwave detection of interstellar NO

    Liszt, H.S., Turner, B.E., 1978. Microwave detection of interstellar NO. The Astrophysical Journal 224, L73. 18

    1978

  20. [20]

    Nitrogen sources and formation routes of nitric oxide from pure ammonia combustion

    Liu, X., Si, J., Wang, G., Wu, M., Mi, J., 2025. Nitrogen sources and formation routes of nitric oxide from pure ammonia combustion. Energy 315, 134455

    2025

  21. [21]

    Electron attach- ment to nitric oxide (NO) controversy

    Lozano, A.I., Oller, J.C., Limão-Vieira, P., García, G., 2025. Electron attach- ment to nitric oxide (NO) controversy. The Journal of Physical Chemistry A 129, 2429–2433

    2025

  22. [22]

    Thirty years of density functional theory in computational chemistry: an overview and extensive assessment of 200 density functionals

    Mardirossian, N., Head-Gordon, M., 2017. Thirty years of density functional theory in computational chemistry: an overview and extensive assessment of 200 density functionals. Molecular Physics 115, 2315–2372

    2017

  23. [23]

    Mason, N.J., Ioppolo, S., Quitián-Lara, H.M., Fantuzzi, F., Mifsud, D.V., Bocková, J., 2026. Foundations of astrochemistry i: Observations and ion- and electron-induced processes in ices, in: Advances in Atomic and Molecular Physics at the Interfaces with Natural Sciences, Technology and Medicine. World Scientific, pp. 575–621

    2026

  24. [24]

    Electron collision with N2H and HCO

    Modak, P., Singh, A., Goswami, B., Antony, B., 2021. Electron collision with N2H and HCO. The European Physical Journal D 75

    2021

  25. [25]

    Total and elastic cross sections for methyl halides by electron impact

    Naghma, R., Antony, B., 2013. Total and elastic cross sections for methyl halides by electron impact. Journal of Electron Spectroscopy and Related Phenomena 189, 17–22

    2013

  26. [26]

    The ORCA quantum chemistry program package

    Neese, F., Wennmohs, F., Becker, U., Riplinger, C., 2020. The ORCA quantum chemistry program package. The Journal of Chemical Physics 152, 224108. NIST, 2025. Computational chemistry comparison and benchmark database. URL: https://cccbdb.nist.gov/

    2020

  27. [27]

    Production of low-energy electrons by ionizing radiation

    Pimblott, S.M., LaVerne, J.A., 2007. Production of low-energy electrons by ionizing radiation. Radiation Physics and Chemistry 76, 1244–1247

    2007

  28. [28]

    Irradiation of organic and polymer films with low-energy electrons

    Sanche, L., 2003. Irradiation of organic and polymer films with low-energy electrons. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 208, 4–10

    2003

  29. [29]

    Differential cross sections for elec- tron/positron scattering from polyatomic molecules

    Sanna, N., Gianturco, F., 1998. Differential cross sections for elec- tron/positron scattering from polyatomic molecules. Computer physics communications 114, 142–167. 19

    1998

  30. [30]

    Adsorption and valence elec- tronic states of nitric oxide on metal surfaces

    Shiotari, A., Koshida, H., Okuyama, H., 2021. Adsorption and valence elec- tronic states of nitric oxide on metal surfaces. Surface Science Reports 76, 100500

    2021

  31. [31]

    A plasma needle generates nitric oxide

    Stoffels, E., Gonzalvo, Y.A., Whitmore, T.D., Seymour, D.L., Rees, J.A., 2006. A plasma needle generates nitric oxide. Plasma Sources Science and Technology 15, 501–506

    2006

  32. [32]

    Electron–molecule collision calculations using the R- matrix method

    Tennyson, J., 2010. Electron–molecule collision calculations using the R- matrix method. Physics Reports 491, 29–76

    2010

  33. [33]

    Quantemol-n: an expert system for performing electron molecule collision calculations using the r-matrix method, in: Journal of Physics: Conference Series, p

    Tennyson, J., Brown, D.B., Munro, J.J., Rozum, I., Varambhia, H.N., Vinci, N., 2007. Quantemol-n: an expert system for performing electron molecule collision calculations using the r-matrix method, in: Journal of Physics: Conference Series, p. 012001

    2007

  34. [34]

    Low-energy electron scattering from pyrrole and its isomers

    Tomer, H., Goswami, B., Modak, P., Alam, M., Ahmad, S., Antony, B., 2023. Low-energy electron scattering from pyrrole and its isomers. The Journal of Physical Chemistry A 127, 10464–10480

    2023

  35. [35]

    Investigation of electron collisions with organic phosphates

    Yadav, A., Antony, B., 2025. Investigation of electron collisions with organic phosphates. The Journal of Physical Chemistry A 129, 8013–8023

    2025

  36. [36]

    A systematic IR and VUV spectroscopic investigation of ion, electron, and thermally processed ethanolamine ice

    Dawes, A., Sivaraman, B., Juhász, Z., Sulik, B., Linnartz, H., Hornekær, L., Fantuzzi, F., Mason, N.J., Ioppolo, S., 2024. A systematic IR and VUV spectroscopic investigation of ion, electron, and thermally processed ethanolamine ice. Monthly Notices of the Royal Astronomical Society 533, 826–840

    2024