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Rubidium zinc trioxide perovskite materials for photovoltaic solar cell applications: A first principle calculations · 10.1016/j.heliyon.2023.e23818

Name: Verified Rigor Record — Rubidium zinc trioxide perovskite materials for photovoltaic solar cell applications: A first principle calculations · 10.1016/j.heliyon.2023.e23818
Item: Rubidium zinc trioxide perovskite materials for photovoltaic solar cell applications: A first principle calculations · 10.1016/j.heliyon.2023.e23818
Rating: 39
Author: Αlpha¹

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Αlpha¹ Editorial

This rigor review was examined and confirmed by Αlpha¹ Editorial · July 6, 2026

Αlpha¹ Rigor Review

Rigor Reviewed

CRITICAL

Critical rigor failure · Computational Study

Eight dimensions — click a segment for details

Critical

High-priority

Model-reported confidence: moderateReviewer agreement: moderateEngine: 7.6.0Source: full text

Not verified in this report

No reported statistical tests were found to recompute.
No data or code availability links were detected to verify.

This Αlpha¹ Rigor Review uses AI Rigor Reviewers trained on a curated corpus of high-fidelity and retracted papers, with expert supervision and curation. It can still make mistakes; verify each finding against the source before relying on it.

Critical findings

• internal_contradiction (high, corroborated): The paper states RbZnO₃ is brittle by Pugh's ratio (B/G = 7.99 > 1.75 → ductile) but then says it is ductile by Poisson's ratio (σ = 0.56 > 0.26 → ductile). The B/G value of 7.99 actually indicates ductility (since >1.75), but the text claims it 'breaks easily' (brittle). This is a clear internal contradiction on a key material property.
• internal_contradiction (high, corroborated): The elastic constant C44 is reported as -40.496 (Table 3), but a negative C44 violates the Born stability criteria for cubic crystals (C44 > 0 is required for mechanical stability). The paper states the elastic characteristics satisfy mechanical stability criteria, which is internally contradictory.
• internal_contradiction (high, corroborated): The paper first states that the material is brittle (based on Pugh's ratio B/G=7.99 > 1.75? Actually 7.99 > 1.75 indicates ductile, but they say 'brittle') and then later states it is ductile based on Poisson's ratio (σ=0.56 > 0.26). The two statements are contradictory.
• impossible_statistic (high, corroborated): C44 is negative (-40.496 GPa). For a cubic crystal, C44 must be positive for mechanical stability. A negative C44 implies instability, contradicting the paper's claim that the compound satisfies mechanical stability criteria.
• internal_contradiction (high, corroborated): The paper claims mechanical stability but reports C44 = -40.496, which is negative and typically indicates instability. The stability conditions are also misstated (C12 > C11 is given, but C12=77.358 < C11=137.868).

This computational DFT study of RbZnO₃ has a clear premise and adequate methods description, but suffers from several serious issues: internal contradictions in the results (negative C44, contradictory brittleness/ductility, band gap type confusion), incomplete references, missing data/code deposition, and a lack of limitation discussion. The paper requires substantial corrections before it can be considered a reliable contribution.

Five dimensions were applicable (biological variables, ethical approvals, statistical analysis were N/A). The three reviewers diverged on scientific premise (one warn) and key resources (one warn), but converged on the major issues of data availability and reporting transparency. The verification components revealed high-severity internal contradictions and an unsupported stability claim.

12 major claims checked against the paper's own evidence: 5 not fully backed by the presented evidence (unsupported or overstated).

10 integrity concerns flagged (5 high).

Rigor

Eight Dimensions3 pass · 1 warn · 1 fail

12 major claims3 unsupported2 overstated2 partial5 supported

The introduction cites multiple prior studies on oxide-perovskites for solar cell applications (e.g., Refs. [1–20]) and notes the need for stable, efficient materials. A specific rationale links the premise to studying RbZnO₃ using DFT. However, the treatment of limitations of prior research is thin — the paper mainly asserts that perovskites solve energy problems without deeply engaging with prior failures or gaps.

Sub-criteria

prior work citedADEQUATE

premise rationaleADEQUATE

limitations addressedINADEQUATE

Per reviewer (3) — the votes behind the verdict

PASSReviewer 1· 95% conf

The paper adequately establishes the scientific premise for studying RbZnO₃ as a potential photovoltaic perovskite, citing prior work and providing a rationale, though the discussion of prior limitations is minimal.

Evidence

direct quote[Introduction, paragraph 1]

“Oxide-perovskites based crystals are the focus of ongoing, extensive research []. This intense interest is sparked by the crystal's fundamental structures, which have a broad spectrum of magneto-resistive, optical, magnetic, catalytic, electric, photovoltaic, and piezoelectric capabilities [].”

direct quote[Introduction, final paragraph]

“In present study, we examined some structural, electrical, optical, and the mechanical properties of RbZnO₃. We studied complete energy estimations by using the generalized GGA-PBE technique with space group 221 Pm3m cubic in nature, which was developed using DFT and is integrated into the CASTEP software.”

direct quote[Introduction, paragraph 6]

“Owing to the absence of a comparable standard manufacturing process for photovoltaic devices based on perovskite compounds LiHfO₃ [], long-term stability in perovskite solar systems has been examined, but it has shown to be an insurmountable challenge [,].”

PASSReviewer 2· 92% conf

The study establishes a clear scientific premise by citing prior perovskite research and provides a logical rationale for investigating RbZnO3 using DFT.

Evidence

direct quote[Introduction, paragraphs 1-6]

“Perovskite solar cell compounds have drawn a lot of interest as a prospective 3rd age solar cell due to their straight forward production technique and outstanding photon-to-electron system transfer energy productivity.”

direct quote[Introduction, paragraph 7]

“In present study, we examined some structural, electrical, optical, and the mechanical properties of RbZnO3.”

absence[Introduction]

Limitations of prior research are not explicitly discussed.

WARNReviewer 3· 70% conf

Prior work is cited but references are incomplete, and limitations of prior research are not addressed; the rationale for the study is adequate.

Evidence

direct quote[Introduction, paragraph 1]

“Oxide-perovskites based crystals are the focus of ongoing, extensive research []. This intense interest is sparked by the crystal's fundamental structures...”

direct quote[Introduction, last paragraph]

“In present study, we examined some structural, electrical, optical, and the mechanical properties of RbZnO3.”

absence[Introduction]

No discussion of limitations of prior research.

For a computational DFT study, randomization, blinding, and biological replicate concepts are not applicable. The design is clearly described: CASTEP software, GGA-PBE functional, USPP, 8×8×8 k-point mesh, cutoff energy 340 eV, energy convergence 5×10⁻⁵ eV, and force tolerance 0.1 eV/Å. The inclusion_exclusion criterion is not reported for data curation (the paper does not mention any selection of structures beyond the initial RbZnO₃). Power_analysis is not applicable as a dataset-selection justification. Replicate_distinction and controls are not applicable for a purely computational property calculation.

Sub-criteria

controlsN/A

power analysisN/A

blinding levelsN/A

outlier handlingN/A

randomization unitN/A

inclusion exclusionNOT REPORTED

randomization methodN/A

replicate distinctionN/A

independent replicationN/A

Per reviewer (3) — the votes behind the verdict

PASSReviewer 1· 90% conf

The computational design is appropriately described: DFT method, software (CASTEP), pseudopotentials, convergence criteria, and k-point mesh are reported. Sub-criteria relevant to computational studies are adequately covered.

Evidence

direct quote[Section 2, Computational detailed]

“The structural, optical and electrical features were determined by the CASTEP program, that is based on DFT [].”

direct quote[Section 2]

“The energy per atom in this instance is 5 × 10⁻⁵ eV. Maximum forces remain acting on atoms after geometry adjustment is 0.1 eV/Å k-integration was set at an 8 × 8 × 8 k-point mesh values on the Monkhorst Pack-Grid (MPG), the cutoff energy for whole Brillouin zone (BZ) was 340.0eV.”

absence[Section 2]

No data curation inclusion/exclusion criteria are reported; the study only examines a single compound.

N/AReviewer 2· 95% conf

As a computational DFT study using standard software, the traditional experimental design criteria are not applicable; the computational methodology is described.

Evidence

direct quote[Section 2: Computational detailed]

“All calculations were done using the GGA-PBE approaches and USP of the CASTEP software which is based on DFT.”

PASSReviewer 3· 80% conf

Computational methods are clearly described, including software parameters and comparison with literature as a control.

Evidence

direct quote[Section 2, Computational detailed]

“k-integration was set at an 8 × 8 × 8 k-point mesh values ... cutoff energy for whole Brillouin zone (BZ) was 340.0eV.”

direct quote[Section 3.1, Table 1]

“Table 1 Compound RbZnO3 lattice constant a (Å), volume V (Å3), bandgap BG (eV), and transition type. ... LiZnO3 [1] 3.55 44.73 4.59 Indirect”

absence[Entire paper]

No independent replication is reported.

All checklist items (sex, age, weight, species, housing, demographics) are irrelevant to a first-principles DFT calculation on an inorganic crystal. No bench or clinical data are involved.

Sub-criteria

demographicsN/A

sex reportedN/A

sex justifiedN/A

age weight healthN/A

housing conditionsN/A

species strain sourceN/A

Per reviewer (3) — the votes behind the verdict

N/AReviewer 1· 100% conf

This is a computational materials science study with no biological organisms, cell lines, or human subjects; therefore, no biological variables are applicable.

Evidence

direct quote[Abstract and Section 1]

“First-principles study of structural adjustment, precise band gap control, and the optical characteristics of oxide perovskites are published for the first time.”

N/AReviewer 2· 99% conf

This is an in silico computational study on a hypothetical material; no biological subjects, cell lines, or organisms are involved.

Evidence

direct quote[Throughout paper]

“The compound is found to be in a stable cubic phase according to our study.”

N/AReviewer 3· 100% conf

No biological subjects or variables are involved; the study is purely computational.

The paper performs first-principles calculations on a hypothetical crystal structure; no experiments on living organisms or human participants are conducted. The authors state 'Ethical approval N/A' which is correct for this type of work.

Sub-criteria

iacuc statementN/A

informed consentN/A

irb ethics statementN/A

regulatory complianceN/A

Per reviewer (3) — the votes behind the verdict

N/AReviewer 1· 100% conf

The study involves no human or animal subjects, tissue, or non-public identifiable data. It is a computational simulation using already-published structural data and a standard DFT code, so ethics approvals are genuinely not applicable.

Evidence

direct quote[After Conclusion, before Declaration]

“Ethical approval N/A.”

N/AReviewer 2· 99% conf

The study is a computational simulation on a hypothetical material with no human or animal subjects, tissue, or non-public identifiable data.

Evidence

direct quote[End of paper, before CRediT statement]

“Ethical approval N/A.”

N/AReviewer 3· 100% conf

The study involves no human or animal subjects, tissue, or non-public identifiable data; ethics approval is not required.

Evidence

direct quote[Ethical approval]

“Ethical approval N/A.”

For a computational-only study, only software_tools_identified is applicable. CASTEP is named as the software package, and the pseudopotential approach (USP) and functional (GGA-PBE) are described. No antibodies, cell lines, mycoplasma, organisms, or experimental reagents are used. The software is identified but without a specific version number (e.g., 'CASTEP 2020'). The inclusion of USP and GGA-PBE partially compensates.

Sub-criteria

mycoplasma testingN/A

reagents identifiedN/A

organisms identifiedN/A

antibodies identifiedN/A

cell line authenticationN/A

software tools identifiedADEQUATE

Per reviewer (3) — the votes behind the verdict

PASSReviewer 1· 95% conf

The key resources (CASTEP software and pseudopotential method) are identified by name and version/approach. No experimental reagents, antibodies, cell lines, or organisms are used, so those sub-criteria are not applicable.

Evidence

direct quote[Abstract and Section 2]

“Exchange generalized gradient approximation (GGA) and Perdew-Burke-Ernzerhof-PBE correlation functionals and density functional theory (DFT)-based Cambridge Serial Total Energy Package (CASTEP) software are used”

absence[Section 2]

No version number for CASTEP is provided.

PASSReviewer 2· 85% conf

The main resource is the CASTEP software, which is adequately identified; no biological reagents, antibodies, or cell lines are used.

Evidence

direct quote[Abstract and Section 2]

“All calculations were done using the GGA-PBE approaches and USP of the CASTEP software which is based on DFT.”

WARNReviewer 3· 70% conf

The software (CASTEP) is identified but without version number; no other key resources are used.

Evidence

direct quote[Abstract]

paraphrase[Entire paper]

“The paper does not mention any antibodies, cell lines, or organisms.”

The paper does not perform any statistical hypothesis testing. It presents computed values for structural, electronic, elastic, and optical properties. No p-values, effect sizes, or confidence intervals are reported.

Sub-criteria

tests namedN/A

exact p valuesN/A

effect sizes ciN/A

data presentationN/A

software identifiedN/A

assumptions verifiedN/A

mathematical plausibilityN/A

Per reviewer (3) — the votes behind the verdict

N/AReviewer 1· 95% conf

The paper reports computed material properties (band gap, elastic constants, optical functions) from first-principles DFT, not inferential statistics. No hypothesis tests, p-values, or confidence intervals are presented, so no statistical analysis criteria apply.

Evidence

direct quote[Section 3]

“4.23 eV compared with Ref. [] is the band gap of RbZnO₃. The ideal RbZnO₃ lattice parameter was found through geometry optimization to be 4.092 Å, volume is 68.51 Å³ and formation energy −1.316eV”

N/AReviewer 2· 95% conf

No inferential statistics are reported; the study presents DFT-calculated properties without any statistical hypothesis testing, p-values, or confidence intervals.

Evidence

direct quote[Results and discussions]

“4.23 eV compared with Ref. [] is the band gap of RbZnO3.”

N/AReviewer 3· 100% conf

No inferential statistical tests are performed; the study reports computed properties without statistical analysis.

The paper contains a data and code availability line stating 'Data and code will be available on reasonable request.' This is a vague statement with no repository, DOI, or managed-access mechanism. No input files, structure files, or CASTEP input scripts are deposited. code_sharing is not_applicable to the extent that proprietary software (CASTEP) is not required to be shared, but any custom inputs or parameters could have been shared. The statement does not meet the 'concrete route' standard for adequacy.

Sub-criteria

code sharingNOT REPORTED

accession numbersN/A

repository depositN/A

data availability statementINADEQUATE

Per reviewer (3) — the votes behind the verdict

WARNReviewer 1· 95% conf

The study states vague data/code availability ('on reasonable request') but provides no repository deposit, accession numbers, or code sharing. This is reported_but_inadequate for a computational paper.

Evidence

direct quote[Data and code availability section]

“Data and code will be available on reasonable request.”

absence[Data and code availability section]

No repository deposit or accession numbers are provided.

FAILReviewer 2· 95% conf

No explicit data or code availability is provided; a statement 'Data and code will be available on reasonable request' is vague and lacks a concrete access route.

Evidence

direct quote[Data and code availability section]

“Data and code will be available on reasonable request.”

absence[Data and code availability section]

No repository deposit or code sharing is mentioned.

FAILReviewer 3· 90% conf

Data and code availability statement is vague ('available on reasonable request'), and no repository deposit or code sharing is provided.

Evidence

direct quote[Data and code availability]

“Data and code will be available on reasonable request.”

absence[Entire paper]

No repository deposit.

absence[Entire paper]

No code repository.

Methods_completeness is reported_but_inadequate: the computational details (CASTEP, k-points, cutoff) are given but lack specifics on pseudopotential generation (e.g., cutoff radii, exchange parameters) and exact convergence criteria for all properties. Trial_registration is not applicable. Reporting_guideline is not_reported — no mention of any checklist (e.g., the GO-FAIR checklist for computational papers). All_outcomes_reported is adequate: all computed properties (structural, electronic, elastic, optical) are reported. Limitations_discussed is adequate: the paper notes the study is at 0 K and the material's ductility/brittleness, but does not discuss DFT intrinsic limitations (e.g., band gap underestimation in GGA, lack of temperature effects). Conclusions_proportional is adequate: the conclusion that the material 'might be used in a solar cell to capture ultraviolet light' is appropriately tentative. Funding_coi is reported_and_adequate: declaration of competing interests and a note on funding (Waqar Azeem: Funding acquisition) are present.

Sub-criteria

funding coiADEQUATE

trial registrationN/A

reporting guidelineNOT REPORTED

methods completenessINADEQUATE

all outcomes reportedADEQUATE

limitations discussedINADEQUATE

conclusions proportionalADEQUATE

Per reviewer (3) — the votes behind the verdict

WARNReviewer 1· 85% conf

The paper provides a basic description of methods and acknowledges limitations and funding/COI, but it lacks a statement of adherence to a computational reporting guideline, and the methods section is not sufficiently detailed for full replication (e.g., pseudopotential specifics, exact functional parameters).

Evidence

direct quote[Section 2]

“The structural, optical and electrical features were determined by the CASTEP program, that is based on DFT []. ... The energy per atom in this instance is 5 × 10⁻⁵ eV. Maximum forces remain acting on atoms after geometry adjustment is 0.1 eV/Å k-integration was set at an 8 × 8 × 8 k-point mesh values on the Monkhorst Pack-Grid (MPG), the cutoff energy for whole Brillouin zone (BZ) was 340.0eV.”

absence[All sections]

No reporting guideline is referenced.

direct quote[Conclusion]

“Materials are semiconductors at 0 K.”

WARNReviewer 2· 80% conf

Methods are described in sufficient detail for reproducibility, but the paper lacks a reporting guideline, a limitations section, and has minor overclaiming in the conclusion.

Evidence

direct quote[Section 2]

“The cutoff energy for whole Brillouin zone (BZ) was 340.0eV.”

absence[Discussion/Conclusion]

No limitations section or discussion of limitations.

direct quote[CRediT authorship contribution statement and Declaration of competing interest]

“The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.”

WARNReviewer 3· 80% conf

Methods are adequately described, all outcomes are reported, and conclusions are proportional, but limitations are not discussed and funding sources are not reported.

Evidence

direct quote[Section 2, Computational detailed]

“All calculations were done using the GGA-PBE approaches and USP of the CASTEP software which is based on DFT.”

absence[Conclusion]

No limitations discussed.

direct quote[Declaration of competing interest]

“The authors declare that they have no known competing financial interests or personal relationships...”

30 copyedit issues flagged (14 major): mostly typo, grammar, clarity.

Checked 40 references: 22 verified — 18 unresolved.

Αlpha¹ Rigor Action ItemsFinal pass before journal submission

This published paper has significant robustness issues that an informed reader should weigh carefully. The internal contradictions (negative C44, contradictory brittleness/ductility, direct vs indirect band gap) and unsupported stability claim are serious validity threats that warrant an erratum or correction. The missing data and code deposition further limit reproducibility.

1.
CRITICALrigor
Address the internal contradiction regarding mechanical stability: the reported C44 = -40.496 GPa violates the Born stability criterion (C44 > 0 required for cubic crystals). Recompute or correct the elastic constants and ensure the stability claim is consistent with the data.
A negative C44 is physically impossible for a mechanically stable cubic crystal; this is a fundamental error that undermines the entire elastic analysis.
2.
CRITICALrigor
Resolve the contradictory statements about brittleness vs. ductility: the paper states both that RbZnO₃ is brittle (based on Pugh's ratio) and ductile (based on Poisson's ratio). Harmonize the interpretation and clearly state which criterion applies.
The paper presents two conflicting mechanical characterizations; readers cannot determine the material's true nature.
3.
CRITICALrigor
Correct the contradiction in band gap type: the results section states the band gap is indirect (4.23 eV), but the conclusion states 'CBM and VBM both perfectly overlap, causing a direct band gap'. Harmonize and ensure consistency.
A direct vs. indirect band gap is a fundamental property; the contradiction invalidates the optical conclusions.
4.
CRITICALdata code
Deposit the CASTEP input files (e.g., .cell, .param, .castep files) in a public repository (e.g., Zenodo, Figshare) with a DOI, and update the data availability statement to include the DOI.
The current vague statement 'on reasonable request' does not meet the reproducibility standards for computational work.
5.
CRITICALreporting
Provide a complete reference list with proper citation numbers; the current empty brackets prevent readers from verifying the cited literature.
Incomplete references undermine the scientific premise and could be a sign of fabrication.
6.
HIGHreporting
Add a limitations section discussing the constraints of the DFT approach, such as the GGA-PBE functional's known band-gap underestimation, zero-temperature calculations, and lack of experimental validation.
Acknowledging limitations is essential for interpreting the results and avoiding overclaiming.
7.
HIGHrigor
Correct the elastic stability condition in Section 3.3: the text states 'C12 > C11' but the data show C12=77.358 < C11=137.868. Fix the condition to C12 < C11.
The stated condition is mathematically incorrect and contradicts the reported values.
8.
HIGHreporting
Provide the version number of the CASTEP software used (e.g., CASTEP 2022) and the exact pseudopotential set (e.g., OTFG ultrasoft pseudopotentials).
Software version is essential for reproducibility; without it, the calculations cannot be exactly replicated.
9.
HIGHreporting
Verify or correct the 18 references that were not found in Crossref/OpenAlex (listed in the citation verification report).
Unresolved references may be fabricated or mis-cited, which is a serious integrity concern.
10.
HIGHrigor
Temper the claim that 'RbZnO₃ could be used in a solar cell to capture ultraviolet light' to reflect that only computed optical properties at 0 K are available, with no device simulation or experimental validation.
The claim is overstated relative to the evidence; it should be presented as a speculative possibility, not a conclusion.
11.
MEDIUMcopyedit
Fix the major grammatical and clarity issues throughout the manuscript, including the incomprehensible sentence in Structural analysis: 'The volume that comprises the balancing cell...' (see copyedit report for 30 issues).
Poor language obscures the scientific content and may reduce credibility.
12.
MEDIUMreporting
Add a statement of adherence to a computational reproducibility guideline (e.g., GO-FAIR checklist for computational papers).
Referencing a guideline demonstrates commitment to reproducibility and helps reviewers.
13.
MEDIUMreporting
Include funding sources and grant numbers in a separate section near the declaration of competing interest.
Funding information is required by most journals and is currently missing.
14.
LOWcopyedit
Resolve the minor formatting issues in keywords and author names (e.g., add commas, use semicolons).
Clean formatting improves the professional appearance of the paper.

Full text (23,190 chars)Analyzed: Jul 6, 2026

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