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Record W4362459705 · doi:10.1107/s205327332300116x

Revisited relativistic Dirac–Hartree–Fock X-ray scattering factors. II. Chemically relevant cations and selected monovalent anions for atoms with <i>Z</i> = 3–112

2023· article· en· W4362459705 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueActa Crystallographica Section A Foundations and Advances · 2023
Typearticle
Languageen
FieldPhysics and Astronomy
TopicCrystallography and Radiation Phenomena
Canadian institutionsUniversity of British Columbia
Fundersnot available
KeywordsHartree–Fock methodScatteringDirac (video compression format)X-rayAtomic physicsPhysicsChemistryRelativistic quantum chemistryQuantum mechanics

Abstract

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The previously described approach for determination of the relativistic atomic X-ray scattering factors (XRSFs) at the Dirac–Hartree–Fock level [Olukayode et al. (2023). Acta Cryst. A 79 , 59–79] has been used to evaluate the XRSFs for a total of 318 species including all chemically relevant cations [Greenwood &amp; Earnshaw (1997). Chemistry of the Elements ], six monovalent anions (O − , F − , Cl − , Br − , I − , At − ), the ns 1 np 3 excited (valence) states of carbon and silicon, and several exotic cations (Db 5+ , Sg 6+ , Bh 7+ , Hs 8+ and Cn 2+ ) for which the chemical compounds have been recently identified, thus significantly extending the coverage relative to all the earlier studies. Unlike the data currently recommended by the International Union of Crystallography (IUCr) [Maslen et al. (2006). International Tables for Crystallography , Vol. C, Section 6.1.1, pp. 554–589], which originate from different levels of theory including the non-relativistic Hartree–Fock and correlated methods, as well as the relativistic Dirac–Slater calculations, the re-determined XRSFs come from a uniform treatment of all species within the same relativistic B-spline Dirac–Hartree–Fock approach [Zatsarinny &amp; Froese Fischer (2016). Comput. Phys. Comm. 202 , 287–303] that includes the Breit interaction correction and the Fermi nuclear charge density model. While it was not possible to compare the quality of the generated wavefunctions with that from the previous studies due to a lack (to the best of our knowledge) of such data in the literature, a careful comparison of the total electronic energies and the estimated atomic ionization energies with experimental and theoretical values from other studies instils confidence in the quality of the calculations. A combination of the B-spline approach and a fine radial grid allowed for a precise determination of the XRSFs for each species in the entire 0 ≤ sin θ/λ ≤ 6 Å −1 range, thus avoiding the necessity for extrapolation in the 2 ≤ sin θ/λ ≤ 6 Å −1 interval which, as was shown in the first study, may lead to inconsistencies. In contrast to the Rez et al. work [ Acta Cryst. (1994), A 50 , 481–497], no additional approximations were introduced when calculating wavefunctions for the anions. The conventional and extended expansions were employed to produce interpolating functions for each species in both the 0 ≤ sin θ/λ ≤ 2 Å −1 and 2 ≤ sin θ/λ ≤ 6 Å −1 intervals, with the extended expansions offering a significantly better accuracy at a minimal computational overhead. The combined results of this and the previous study may be used to update the XRSFs for neutral atoms and ions listed in Vol. C of the 2006 edition of International Tables for Crystallography .

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesScience and technology studies
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.522
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.002
Science and technology studies0.0010.000
Scholarly communication0.0000.001
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.009
GPT teacher head0.239
Teacher spread0.230 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it