Evidence map›Paper›PMID 41809075›Full record

ArticleRSC advances2026

Which

Ivar Kuusik, Antti Kivimäki, Vambola Kisand

Abstract read
In one paragraph

Article in RSC advances, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Ivar KuusikInstitute of Physics, University of Tartu Tartu Estonia ivark@ut.ee.ORCID https://orcid.org/0000-0001-7494-6614
Antti KivimäkiMAX IV Laboratory, Lund University Lund Sweden.ORCID https://orcid.org/0000-0003-0753-8164
Vambola KisandInstitute of Physics, University of Tartu Tartu Estonia ivark@ut.ee.ORCID https://orcid.org/0000-0001-9765-055X

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Time-of-flight mass-spectrometry (TOF-MS) measurements of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][OTF]) vapors have been conducted in order to gain insight into the VUV (vacuum ultraviolet) absorption thresholds. The experimental data were interpreted with hybrid density-functional theory (DFT), time-dependent DFT (TD-DFT), and several flavours of many-body perturbation theory (MBPT): second-order MBPT, Hedin's GW and Bethe-Salpeter equation (BSE) calculations. To our knowledge, this is the first comprehensive comparison of DFT functionals for an ionic liquid (IL) vapor. More than 60 exchange-correlation approximations, including many range-separated hybrids (RSHs) and optimally tuned variants, were assessed. The theoretical methods predicted a wide range of energies; only the experimental TOF-MS data allowed the truly predictive approaches to be identified. The experimental spectra reveal charge transfer (CT) states at an optical gap of 6.75 eV and a maximum ion yield signal at 8.3 eV. Combining the experiment and theory enabled the re-examination of the ion-pair geometry and the reconstruction of the frontier orbitals of [EMIM][OTF]. The HOMO and LUMO energies were found to be -9.05 eV and -2.30 eV, respectively; energies for HOMO-1 and LUMO+1 were also determined. Although a ΔSCF calculation with the non-hybrid M11-L functional gives a reasonable ionization threshold, ≥50% exact Hartree-Fock (HF) exchange is required to correctly describe both the optical gap and the ultraviolet photoemission spectrum (UPS). The RCAM-B3LYP functional and the Bartlett's QTP family of functionals showed good performance in predicting the CT excitations from TD-DFT calculations. No method was able to predict the proposed LUMO energy, though the M08-SO functional was closest overall. Within the limitations of the present work, the global hybrid PBE-2X functional demonstrates the most consistent overall performance. Its range-separated hybrid (RSH) analogue CAM-PBE50* also performed well for the calculation of CT excitations.

Identifiers

PMID41809075
PMCPMC12970537

What OpenQuestion holds

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.