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REVIEW 2 major objections 6 minor 73 references

Linear and nonlinear X-ray spectra of chiral molecules: X-ray Circular Dichroism, Sum- and Difference-Frequency Generation of fenchone and cysteine

T0 review · 2 major / 6 minor · reviewed 2026-08-10 · deepseek-v4-flash

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Pith's one-line read Simulations show that X-ray circular dichroism and optical/X-ray sum- and difference-frequency generation can localize molecular chirality to individual atoms, with the strongest signals at chiral centers.

desk verdict Solid computational study with a clever new 2D valence-core chirality map, but the cysteine predictions rest on the neutral molecule while the proposed experiment is on the zwitterion. read the letter →

arxiv 2501.14671 v1 pith:KIK6DKCR submitted 2025-01-24 physics.chem-ph

Yeonsig Nam , Majed Chergui , Linda Young , Jérémy R. Rouxel This is my paper · ORCID
classification physics.chem-ph
keywords X-raycirculardichroismsum-frequencygenerationdifference-frequencymolecularchiralitycore-excitedstatesfenchonecysteinefree-electronlasers
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

This paper argues that X-ray versions of two established chiral spectroscopies, circular dichroism and sum/difference-frequency generation, can localize molecular handedness to specific atoms. Simulating fenchone and cysteine at their carbon and oxygen K-edges, it finds that X-ray circular dichroism is strongest at the chiral centers and weaker for distant atoms, so the atoms that dominate ordinary absorption need not dominate the chiral response. It also computes optical/X-ray sum- and difference-frequency signals, shows they are dominated by the chiral carbon, and uses them to propose two-dimensional valence-core spectra that connect valence excitations to local asymmetry. The practical payoff is a predicted photon flux of $10^6$ to $10^8$ photons per second with realistic X-ray free-electron laser parameters, suggesting such experiments can be attempted on liquid samples.

What carries the argument

The linear signal is carried by the rotatory strength $R_{cg} = \operatorname{Im}(\boldsymbol{\mu}_{gc}\cdot \mathbf{m}_{cg})$, summed over core-excited states to give the XCD dissymmetry spectrum; the paper computes it in velocity gauge, $R_{cg} \propto \langle g|\nabla|c\rangle \cdot \langle c|\mathbf{r}\times\nabla|g\rangle / \omega_{cg}$, so the result does not depend on the coordinate origin. The nonlinear signals are carried by the electric-dipole triple product $\sum_{ec} \boldsymbol{\mu}_{gc}\cdot(\boldsymbol{\mu}_{ce}\times\boldsymbol{\mu}_{eg})$ for SFG (and the corresponding $\boldsymbol{\mu}_{ec}\cdot(\boldsymbol{\mu}_{cg}\times\boldsymbol{\mu}_{eg})$ for DFG), weighted by resonant propagators and multiplied by the polarization factor $|\mathbf{e}_s^*\cdot(\mathbf{e}_x\times\mathbf{e}_o)|^2$. Because the core orbital is localized on a specific carbon or oxygen atom, each term in these sums reports on the asymmetry of the environment around that atom; the triple product is what makes the nonlinear signal vanish in achiral media and gives the emitted photon its direction and chirality content.

What would settle it

Measure carbon K-edge XCD or optical/X-ray SFG/DFG of liquid fenchone or aqueous cysteine and compare the relative intensities assigned to each carbon; the central prediction is that the chiral-center carbons dominate even though other carbons dominate ordinary absorption. The claim would be undercut if the measured dissymmetry follows the brightest absorber rather than the stereogenic carbon, or if a conformer- and solvent-averaged calculation reverses the ordering of the carbon contributions.

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Extended reading notes

Core claim

The paper claims that extending circular dichroism and sum/difference-frequency generation to core-resonant X-rays turns chirality into a local, atom-resolved observable. In multireference simulations of fenchone and cysteine, XCD intensity concentrates at the stereogenic carbons and decays with distance, so chemically inequivalent carbons of the same element give distinct chiral signatures; the brightest X-ray absorbers are not the brightest chiral emitters. For the nonlinear signals, the same site selectivity appears in the triple products of electric transition dipoles, and scanning both optical and X-ray frequencies yields two-dimensional valence-core spectra that reveal which valence excitations overlap the asymmetric core environment. The paper further claims that with 20 microjoule optical pulses and 10 microjoule X-ray pulses at 100 hertz, the computed fluxes of $10^6$ to $10^8$ photons per second make these experiments feasible at current X-ray free-electron lasers.

Load-bearing premise

The spectra come from a single optimized gas-phase geometry per molecule, and if the conformations a molecule actually visits in solution shift the chiral signals substantially, the predicted dominance of the chiral-center atoms may not survive in the liquid-phase measurements the paper targets.

Editorial extensions

If this is right

  • Because core orbitals are localized, X-ray circular dichroism can separate chemically inequivalent atoms of the same element; two carbons in one molecule can therefore give unequal or even opposite chiral contributions.
  • Optical/X-ray SFG and DFG are electric-dipole-only signals, so they offer a background-free chirality probe that does not require circularly polarized X-ray pulses.
  • Scanning both the optical and the X-ray frequency yields two-dimensional valence-core spectra whose features map which valence excitations overlap the asymmetric environment of each core orbital.
  • With the stated pulse parameters, the simulated signals of $10^6$ to $10^8$ photons per second indicate that the experiments are feasible at current X-ray free-electron laser facilities.
  • Homodyne detection of OX SFG/DFG senses chirality but not its handedness; enantiomer discrimination would require heterodyne detection, which the paper judges to be out of reach for now with intense X-ray pulses.

Reading between the lines

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

  • Inference: because the XCD signal falls off with distance from the chiral center, time-resolved XCD at a single K-edge could act as a local clock for symmetry breaking during a chemical reaction, although the paper only computes static spectra.
  • Inference: the two-dimensional valence-core logic should transfer to nitrogen and sulfur K-edges, where a sulfur atom sits near the chiral center of cysteine; simulating those edges would test whether the site selectivity becomes even sharper.
  • Inference: the flux estimates assume thin samples and neglect detector losses, so a first demonstration may need high-repetition-rate sources or optimized sample delivery; the paper flags detection efficiency but does not quantify it.
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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

2 major / 6 minor

Summary. This paper reports ab initio simulations of X-ray circular dichroism (XCD) and optical/X-ray sum- and difference-frequency generation (OX SFG/DFG) spectra for fenchone and cysteine at the carbon and oxygen K-edges, using multi-reference CASSCF/RASSCF methods and MP2/cc-pVDZ geometries. The authors compute origin-invariant rotatory strengths in the velocity gauge, compare X-ray absorption and UV spectra to available experimental data after rigid energy shifts, and introduce two-dimensional valence-core chirality-sensitive spectroscopy. The central claims are that XCD and OX SFG/DFG are element- and site-specific probes of local chirality, that the strongest chiral responses occur at the chiral centers, and that the proposed nonlinear experiments are feasible at XFELs with photon fluxes of 10^6–10^8 photons/s.

Significance. If the predictions are robust, the paper provides a valuable theoretical foundation for new X-ray-based chiral spectroscopies that combine element specificity with local chirality sensitivity, complementing optical CD and PECD. The calculations are state-of-the-art for this class of problems, and the paper is commendably explicit that no experimental XCD spectra exist for these molecules, making the predictions falsifiable. The feasibility estimates with realistic XFEL parameters offer concrete guidance for experimental design. The main risk to the central claim is the transferability of the reported gas-phase, single-conformer, neutral-molecule results to the proposed liquid-phase experiments, especially for cysteine.

major comments (2)
  1. [§2.2 and §5] The cysteine spectra are computed for a single isolated neutral molecule (MP2/cc-pVDZ optimized geometry), but the proposed experiment in Section 5 targets 2 M aqueous cysteine, where the dominant species at the isoelectric point is the zwitterion (NH3+-CH(CH2SH)-COO-). The rotatory strengths in Eq. (4) and the transition-dipole triple products in Eqs. (5)–(6) depend on the electronic structure near the chiral center, and protonation of the amino group and deprotonation of the carboxyl group will modify the relevant magnetic dipole and core–valence matrix elements. The manuscript nowhere states the protonation state, and the comparison to solid-film XAS (Ref. 66) after rigid energy shifts does not validate the rotatory strengths, which are unshifted and sign-sensitive. The predicted dominance of C6 in the cysteine XCD and SFG/DFG spectra may therefore be an artifact of the neutral form rather than a robust property of the chiral center in solution.
  2. [§3, cysteine paragraph] The manuscript acknowledges that 'an additional broadening of the peaks is expected due to the presence of multiple conformers in the solution phase,' yet all spectra are computed from a single optimized geometry without conformational averaging or solvent effects. Rotatory strengths and the nonlinear dipoles in Eqs. (5)–(6) can change sign across conformers, so the computed XCD and SFG/DFG spectra for cysteine may not represent the solution-phase ensemble. A conformational analysis with Boltzmann averaging over low-energy conformers is needed to determine whether the site-specific predictions—especially the dominance of the chiral carbon—are robust. This is load-bearing for the cysteine part of the central claim.
minor comments (6)
  1. [§1] In the sentence 'soft X-ray absorption spectroscopy of liquid samples is now possible and and their study by soft X-ray CD studies can therefore be envisioned,' the word 'and' is duplicated.
  2. [§2.1, after Eq. (2)] The phrase 'ωcg and Γcg and the transition frequencies' is grammatically incomplete; it should read 'ωcg and Γcg are the transition frequencies and linewidths, respectively.'
  3. [Fig. 4 caption] The caption contains a duplicated 'and': 'Absorption (top) and and CD dissymmetry spectra g(%) (bottom) of cysteine.'
  4. [§4, first paragraph] The phrase 'have a a photon energy ωo' contains a duplicated 'a' and should be corrected.
  5. [§5, photon-flux paragraph] The notation '1 to 100×10^6 ph/s' is awkward and potentially confusing; it should be written as '10^6 to 10^8 photons/s'.
  6. [Abstract] The abstract states that 'multi-reference simulations reproduce experimental data when available,' but only absorption spectra are compared; the UV CD comparisons show notable deviations and no XCD data are available. Clarifying that the agreement refers to absorption spectra would be more precise.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity found: chiral signals are computed from ab initio transition dipoles; empirical adjustments are limited to uniform energy shifts and broadenings that do not constrain the chiral observables.

full rationale

The paper's derivation chain is self-contained. XCD spectra are obtained from rotatory strengths computed with velocity-gauge electric and magnetic transition dipole matrix elements (Eq. 4), and the OX SFG/DFG signals from triple products of ab initio electric dipoles with resonant propagators (Eqs. 5-6). No parameter entering the chiral signal itself is fitted to the target result: the only empirical adjustments reported are uniform energy shifts and phenomenological line broadenings applied to absorption spectra (e.g., 0.7 eV UV shift for fenchone, 2.2-3.2 eV K-edge shifts, 0.1-0.5 eV broadenings). These cannot determine the signs or relative magnitudes of rotatory strengths or dipole triple products, which are the quantities responsible for the site-specific chiral features. The central conclusion that XCD is strongest at chiral centers is supported by the paper's own computed spectra (e.g., dominant C6 contribution in cysteine XCD, Fig. 4e) and not merely borrowed from prior work. Self-citations such as [71] for the qualitative distance-dependence statement are contextual, and the same trend is visible in the present calculations, so they are not load-bearing. The manuscript also openly flags limitations (no liquid-phase XCD data yet, expected conformer broadening for cysteine), which is consistent with a genuinely predictive computation rather than a circular one. Consequently, no step reduces by construction to its inputs.

Assumptions & free parameters 5 free parameters · 5 assumptions · 0 invented entities

The central predictions rest on a standard electronic-structure protocol with several fitted energy shifts and line broadenings. The agreement with XAS is used to justify confidence in the CD results, but the CD itself is not experimentally validated, and geometry or solvent simplifications are only partially acknowledged.

free parameters (5)
  • Fenchone UV energy shift = 0.7 eV
    Applied uniformly to all computed valence transition energies in Figure 3a to match the experimental UV absorption spectrum (Section 3).
  • Fenchone C K-edge energy shift = 2.2 eV
    Applied to C1s core-excited state energies in Figure 3b to align with experimental XAS (Section 3).
  • Cysteine C K-edge energy shift = 2.7 eV
    Applied to C1s excited states in Figure 4b to match experimental XAS (Section 3).
  • Cysteine O K-edge energy shift = 3.2 eV
    Applied to O1s excited states in Figure 4c to match experimental XAS (Section 3).
  • Phenomenological Lorentzian broadenings = 0.1-0.5 eV depending on edge
    Chosen to reproduce the observed spectral widths; not derived from first principles.
assumptions (5)
  • domain assumption Field-matter interaction truncated at magnetic dipole order; E1/E2 quadrupole contributions vanish for isotropic ensembles.
    Invoked in Section 2.1 to derive XCD equation (Eq. 2). Valid for randomly oriented liquid samples.
  • domain assumption Velocity-gauge rotatory strengths are origin-invariant.
    Used to compute Eq. 4; authors verify by random translation/rotation in Section 2.2.
  • domain assumption The chosen CASSCF/RASSCF active spaces and basis sets sufficiently describe core and valence excitations.
    Section 2.2; supported only by comparison to experimental absorption, not to CD.
  • ad hoc to paper A single optimized geometry is representative of the molecule in solution.
    Section 2.2 optimizes MP2/cc-pVDZ geometries; Section 3 acknowledges conformer broadening but does not average over conformers or include solvent.
  • domain assumption Only the X-ray resonance at the lowest core transition is considered for DFG; off-resonant contributions are neglected.
    Stated in Section 4 for the DFG pathway; may affect quantitative signal and spectral shape.

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Cite this review

Pith. "Pith review of Linear and nonlinear X-ray spectra of chiral molecules: X-ray Circular Dichroism, Sum- and Difference-Frequency Generation of fenchone and cysteine." pith.science (2026). https://pith.science/paper/KIK6DKCR

@misc{pith2026250114671,
  author       = {Pith},
  title        = {Pith review of: Linear and nonlinear X-ray spectra of chiral molecules: X-ray Circular Dichroism, Sum- and Difference-Frequency Generation of fenchone and cysteine},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/KIK6DKCR}},
  note         = {Machine review of arXiv:2501.14671}
}
read the original abstract

Recent advancements in X-ray light sources at synchrotrons and X-ray free-electron lasers (XFELs) present exciting opportunities to probe molecular chirality using novel nonlinear spectroscopies with element-sensitivity. Circular dichroism (CD) and sum- and difference-frequency generation (SFG/DFG) are established techniques for probing molecular asymmetry in optical regime, with SFG/DFG offering unique advantages due to their background-free nature and independence from circularly polarized light sources. Extending them into the X-ray domain provides deeper insights into local structural asymmetries by leveraging the localized nature of core orbitals. In this work, we simulate X-ray absorption spectroscopy (XAS), X-ray circular dichroism (XCD) and nonlinear optical/X-ray SFG and DFG (OX SFG/DFG) signals for two prototypical chiral molecules, fenchone and cysteine. Our multi-reference simulations reproduce experimental data when available and reveal how novel X-ray spectroscopies exploit the site- and element-sensitivity of X-rays to uncover molecular asymmetry. The XCD spectra show strong asymmetries at chiral centers, while distant atoms contribute less. The OX SFG/DFG signals, under fixed resonant optical excitation, strongly depend on core transition and valence excitation energies. This dependence allows us to introduce two-dimensional (2D) chirality-sensitive valence-core spectroscopy, which provides insight into the overlap between valence orbitals and local molecular asymmetry. Finally, our estimates using realistic laser and X-ray pulse parameters demonstrate that such nonlinear experiments are feasible at XFELs, offering a promising tool for investigating the geometric and electronic structures of chiral molecules.

Figures

Figures reproduced from arXiv: 2501.14671 by the authors.

Figure 1
Figure 1. Skeletal formula of L- and D-fenchone ((1R,4S)– and (1S,4R)–fenchone respectively) (a) and of L- and D-cysteine (b). The atom numbering is used throughout the text for peak assignment. The chiral centers are indicated by orange and blue circles. The chiral response of atoms is found to depend on their chemical environment, thus adding a parameter to distinguish iso-elemental but inequivalent atoms in a polyatomic mo… view at source ↗
Figure 2
Figure 2. Geometry of a) X-ray Circular Dicrho￾ism (XCD) and; b) Optical/X-ray SFG/DFG detection schemes. c) and d) k-vector diagrams for SFG and DFG, respectively. The wave vectors are not displayed in real scale, since the X-ray wave vector amplitude is much larger that the optical one. e) and f) Ladder di￾agrams contributing to the SFG and DFG spectra re￾spectively. °C. [54]) Fenchone is a naturally occurring compound used… view at source ↗
Figure 3
Figure 3. Absorption spectra (top) and CD dissymmetry spectra g(%) (bottom) of fenchone. Spectra are com [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
Figures from the paper (3 more)
Figure 4
Figure 4. Figure 4: Absorption (top) and and CD dissymmetry spectra g(%) (bottom) of cysteine. Spectra are computed [PITH_FULL_IMAGE:figures/full_fig_p005_4.png]
Figure 5
Figure 5. Figure 5: X-ray Sum-Frequency Generation (a and c) [PITH_FULL_IMAGE:figures/full_fig_p006_5.png]
Figure 6
Figure 6. Figure 6: Valence-core two-dimensional (2D) optical/X-ray (OX) SFG and DFG spectra of fen￾chone (a and b) and cysteine (c and d). The vertical red lines indicate the slices displayed in [PITH_FULL_IMAGE:figures/full_fig_p007_6.png]

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Works this paper leans on

73 extracted references · 73 canonical work pages

  1. [1]

    Pas- teur and chirality: A story of how serendipity fa- vors the prepared minds

    Ghislaine Vantomme and Jeanne Crassous. Pas- teur and chirality: A story of how serendipity fa- vors the prepared minds. Chirality, 33(10):597– 601, 2021

    work page 2021

  2. [2]

    Circular dichroism: principles and applica- tions

    Nina Berova, Koji Nakanishi, and Robert W Woody. Circular dichroism: principles and applica- tions. John Wiley & Sons, 2000

    work page 2000

  3. [3]

    Vibrational circular dichro- ism

    Laurence A Nafie, TA Keiderling, and PJ Stephens. Vibrational circular dichro- ism. Journal of the American Chemical Society , 98(10):2715–2723, 1976

    work page 1976

  4. [4]

    The current state of ab initio calcula- tions of optical rotation and electronic circular 8 dichroism spectra

    T Daniel Crawford, Mary C Tam, and Micah L Abrams. The current state of ab initio calcula- tions of optical rotation and electronic circular 8 dichroism spectra. The Journal of Physical Chem- istry A, 111(48):12057–12068, 2007

    work page 2007

  5. [5]

    Optical rotation: recent advances in determining the absolute configura- tion

    Prasad L Polavarapu. Optical rotation: recent advances in determining the absolute configura- tion. Chirality, 14(10):768–781, 2002

    work page 2002

  6. [6]

    Raman optical activity comes of age

    Laurence D Barron, Lutz Hecht, Iain H McColl, and Ewan W Blanch. Raman optical activity comes of age. Molecular Physics, 102(8):731–744, 2004

    work page 2004

  7. [7]

    Application of electronic circular dichroism in configurational and conformational analysis of organic compounds

    Nina Berova, Lorenzo Di Bari, and Gennaro Pescitelli. Application of electronic circular dichroism in configurational and conformational analysis of organic compounds. Chemical Society Reviews, 36(6):914–931, 2007

    work page 2007

  8. [8]

    Fluorescence detected cir- cular dichroism (fdcd) for supramolecular host– guest complexes

    Amrutha Prabodh, Yichuan Wang, Stephan Sinn, Paolo Albertini, Christian Spies, Eduard Spul- ing, Liu-Pan Yang, Wei Jiang, Stefan Br ¨ase, and Frank Biedermann. Fluorescence detected cir- cular dichroism (fdcd) for supramolecular host– guest complexes. Chemical science , 12(27):9420– 9431, 2021

    work page 2021

Show all 73 references
  1. [9]

    Detecting chirality in molecules by imaging photoelectron circular dichroism

    Maurice HM Janssen and Ivan Powis. Detecting chirality in molecules by imaging photoelectron circular dichroism. Physical Chemistry Chemical Physics, 16(3):856–871, 2014

    2014

  2. [10]

    Conformational effects in photoelec- tron circular dichroism

    S Turchini. Conformational effects in photoelec- tron circular dichroism. Journal of Physics: Con- densed Matter, 29(50):503001, 2017

    2017

  3. [11]

    Real-time probing of chirality during a chemical reaction

    Denitsa Baykusheva, Daniel Zindel, V´ıt Svoboda, Elias Bommeli, Manuel Ochsner, Andres Tehlar, and Hans Jakob W ¨orner. Real-time probing of chirality during a chemical reaction. Proceedings of the National Academy of Sciences, 116(48):23923– 23929, 2019

    2019

  4. [12]

    D Faccial `a, M Devetta, S Beauvarlet, N Besley, F Calegari, C Callegari, D Catone, E Cinquanta, AG Ciriolo, L Colaizzi, et al. Time-resolved chi- ral x-ray photoelectron spectroscopy with tran- siently enhanced atomic site selectivity: a free- electron laser investigation of ...

    2023

  5. [13]

    Captur- ing electron-driven chiral dynamics in uv-excited molecules

    Vincent Wanie, Etienne Bloch, Erik P M ˚ansson, Lorenzo Colaizzi, Sergey Ryabchuk, Krishna Saraswathula, Andres F Ordonez, David Ayuso, Olga Smirnova, Andrea Trabattoni, et al. Captur- ing electron-driven chiral dynamics in uv-excited molecules. Nature, pages 1–7, 2024

    2024

  6. [14]

    Photoelectron circu- lar dichroism in angle-resolved photoemission from liquid fenchone

    Marvin N Pohl, Sebastian Malerz, Florian Trin- ter, Chin Lee, Claudia Kolbeck, Iain Wilkinson, Stephan Th ¨urmer, Daniel M Neumark, Laurent Nahon, Ivan Powis, et al. Photoelectron circu- lar dichroism in angle-resolved photoemission from liquid fenchone. Physical Chemistry Che...

    2022

  7. [15]

    A setup for studies of photoelec- tron circular dichroism from chiral molecules in aqueous solution

    Sebastian Malerz, Henrik Haak, Florian Trin- ter, Anne B Stephansen, Claudia Kolbeck, Mar- vin Pohl, Uwe Hergenhahn, Gerard Meijer, and Bernd Winter. A setup for studies of photoelec- tron circular dichroism from chiral molecules in aqueous solution. Review of Scientific Instr...

    2022

  8. [16]

    X-ray nat- ural circular dichroism

    Paolo Carra and Robert Benoist. X-ray nat- ural circular dichroism. Physical Review B , 62(12):R7703, 2000

    2000

  9. [17]

    Near-edge x-ray absorption and nat- ural circular dichroism spectra of l-alanine: A theoretical study based on the complex polariza- tion propagator approach

    Auayporn Jiemchooroj, Ulf Ekstr ¨om, and Patrick Norman. Near-edge x-ray absorption and nat- ural circular dichroism spectra of l-alanine: A theoretical study based on the complex polariza- tion propagator approach. The Journal of chemical physics, 127(16), 2007

    2007

  10. [18]

    Cal- culation of k-edge circular dichroism of amino acids: Comparison of random phase approxima- tion with other methods

    Victor Kimberg and Nobuhiro Kosugi. Cal- culation of k-edge circular dichroism of amino acids: Comparison of random phase approxima- tion with other methods. The Journal of chemical physics, 126(24), 2007

    2007

  11. [19]

    X- ray absorption and natural circular dichroism spectra of c84: A theoretical study using the com- plex polarization propagator approach

    Auayporn Jiemchooroj and Patrick Norman. X- ray absorption and natural circular dichroism spectra of c84: A theoretical study using the com- plex polarization propagator approach. The Jour- nal of chemical physics, 128(23), 2008

    2008

  12. [20]

    Sebastien Villaume and Patrick Norman. On circular dichroism and the separation between chromophore and chiral center: The near car- bon k-edge x-ray absorption and circular dichro- ism spectra of noradrenaline and l-dopa. Chiral- ity: The Pharmacological, Biological, and Chem...

    2009

  13. [21]

    Theoretical study of the x-ray natu- ral circular dichroism of some crystalline amino acids

    Osamu Takahashi, Mai Kimoto, and Lars GM Pettersson. Theoretical study of the x-ray natu- ral circular dichroism of some crystalline amino acids. Chemical Physics, 450:109–114, 2015

    2015

  14. [22]

    On the calcula- tion of an x-ray natural circular dichroism signal

    AP Oreshko, EN Ovchinnikova, KA Ko- zlovskaya, and VE Dmitrienko. On the calcula- tion of an x-ray natural circular dichroism signal. Moscow University Physics Bulletin , 73:314–324, 2018

    2018

  15. [23]

    Freixas, J ´er´emy R

    Victor M. Freixas, J ´er´emy R. Rouxel, Yeonsig Nam, Sergei Tretiak, Niranjan Govind, and Shaul Mukamel. X-ray and optical circular dichro- ism as local and global ultrafast chiral probes of [12]helicene racemization. Journal of the Ameri- can Chemical Society , 145(38):21012–...

    2023

  16. [24]

    Rouxel, Daniel Keefer, Niranjan Govind, and Shaul Mukamel

    Yeonsig Nam, Daeheum Cho, Bing Gu, J´er´emy R. Rouxel, Daniel Keefer, Niranjan Govind, and Shaul Mukamel. Time-evolving chirality loss in molecular photodissociation monitored by x-ray circular dichroism spectroscopy. Journal of the 9 American Chemical Society , 144(44):20400–20410,

  17. [25]

    X-ray natural circu- lar dichroism

    Lucilla Alagna, Tommaso Prosperi, Stefano Tur- chini, Jos ´e Goulon, Andrei Rogalev, Chantal Goulon-Ginet, Calogero R Natoli, Robert D Pea- cock, and Brian Stewart. X-ray natural circu- lar dichroism. Physical review letters, 80(21):4799, 1998

    1998

  18. [26]

    X-ray natural circular dichroism in a uniaxial gyrotropic single crystal of liio 3

    Jos ´e Goulon, Chantal Goulon-Ginet, Andrei Ro- galev, Vincent Gotte, C´ecile Malgrange, Christian Brouder, and Calogero R Natoli. X-ray natural circular dichroism in a uniaxial gyrotropic single crystal of liio 3. The Journal of chemical physics , 108(15):6394–6403, 1998

    1998

  19. [27]

    Circular dichroism at the edge: Large x-ray natural cd in the 1s → 3d pre-edge feature of 2 [co (en) 3 cl 3]· nacl· 6h 2 o

    Brian Stewart, Robert D Peacock, Lucilla Alagna, Tommaso Prosperi, Stefano Turchini, Jos ´e Goulon, Andrei Rogalev, and Chantal Goulon- Ginet. Circular dichroism at the edge: Large x-ray natural cd in the 1s → 3d pre-edge feature of 2 [co (en) 3 cl 3]· nacl· 6h 2 o. Journal of...

    1999

  20. [28]

    Natural cir- cular dichroism in x-ray spectroscopy, 2001

    Robert D Peacock and Brian Stewart. Natural cir- cular dichroism in x-ray spectroscopy, 2001

    2001

  21. [29]

    Natural circu- lar dichroism of amino acid films observed in soft x-ray and vuv region using polarizing undulator

    Kazumichi Nakagawa, F Kaneko, Y Ohta, M Tanaka, T Kitada, A Agui, F Fujii, A Yokoya, K Yagi-Watanabe, and T Yamada. Natural circu- lar dichroism of amino acid films observed in soft x-ray and vuv region using polarizing undulator. Journal of electron spectroscopy and related p...

    2005

  22. [30]

    First observation of natural circular dichroism for biomolecules in soft x-ray region studied with a polarizing undulator

    Masahito Tanaka, Kazumichi Nakagawa, Akane Agui, Kentaro Fujii, and Akinari Yokoya. First observation of natural circular dichroism for biomolecules in soft x-ray region studied with a polarizing undulator. Physica Scripta , 2005(T115):873, 2005

    2005

  23. [31]

    Characteristic oxygen k-edge circular dichroism spectra of amino acid films by improved mea- surement technique

    Yudai Izumi, Maiko Tanabe, Akiko Imazu, Aki Mimoto, Masahito Tanaka, Akane Agui, Takayuki Muro, and Kazumichi Nakagawa. Characteristic oxygen k-edge circular dichroism spectra of amino acid films by improved mea- surement technique. The Journal of Chemical Physics, 138(7), 2013

    2013

  24. [32]

    Core electron transitions as a probe for molecular chirality: Natural cir- cular dichroism at the carbon k-edge of methy- loxirane

    Stefano Turchini, Nicola Zema, Stefano Zennaro, Lucilla Alagna, Brian Stewart, Robert D Peacock, and Tommaso Prosperi. Core electron transitions as a probe for molecular chirality: Natural cir- cular dichroism at the carbon k-edge of methy- loxirane. Journal of the American Ch...

    2004

  25. [33]

    Progress and prospects in nonlinear extreme- ultraviolet and x-ray optics and spectroscopy

    Majed Chergui, Martin Beye, Shaul Mukamel, Cristian Svetina, and Claudio Masciovecchio. Progress and prospects in nonlinear extreme- ultraviolet and x-ray optics and spectroscopy. Nature Reviews Physics, 5(10):578–596, 2023

    2023

  26. [34]

    A liquid flatjet system for solution phase soft-x- ray spectroscopy

    Maria Ekimova, Wilson Quevedo, Manfred Faubel, Philippe Wernet, and Erik TJ Nibbering. A liquid flatjet system for solution phase soft-x- ray spectroscopy. Structural Dynamics, 2(5), 2015

    2015

  27. [35]

    Soft x-ray ab- sorption spectroscopy of aqueous solutions us- ing a table-top femtosecond soft x-ray source

    Carlo Kleine, Maria Ekimova, Gildas Goldsztejn, Sebastian Raabe, Christian Str ¨uber, Jan Lud- wig, Suresh Yarlagadda, Stefan Eisebitt, Marc JJ Vrakking, Thomas Elsaesser, et al. Soft x-ray ab- sorption spectroscopy of aqueous solutions us- ing a table-top femtosecond soft x-r...

    2018

  28. [36]

    Time- resolved soft x-ray absorption spectroscopy in transmission mode on liquids at mhz repetition rates

    Mattis Fondell, Sebastian Eckert, Raphael M Jay, Christian Weniger, Wilson Quevedo, Johannes Niskanen, Brian Kennedy, Florian Sorgenfrei, Daniel Schick, Erika Giangrisostomi, et al. Time- resolved soft x-ray absorption spectroscopy in transmission mode on liquids at mhz repeti...

    2017

  29. [37]

    A sub-100 nm thickness flat jet for extreme ultraviolet to soft x-ray absorption spectroscopy

    Dario De Angelis, Luca Longetti, Gabriele Bo- nano, Jacopo Stefano Pelli Cresi, Laura Foglia, Matteo Pancaldi, Flavio Capotondi, Emanuele Pedersoli, Filippo Bencivenga, Marija Krstulovic, et al. A sub-100 nm thickness flat jet for extreme ultraviolet to soft x-ray absorption s...

    2024

  30. [38]

    Poldi, Carlos A

    Eduardo H.T. Poldi, Carlos A. Escanhoela Jr, Jairo Fonseca Jr, Marcos A.S. Eleot ´erio, Ricardo D. Dos Reis, Jonathan C. Lang, Daniel Haskel, and Narcizo M. Souza-Neto. A versatile X-ray phase retarder for lock-in XMCD measurements. Journal of Synchrotron Radiation , 27(5):124...

    2020

  31. [39]

    Possibil- ities at the polar beamline with aps-u

    Joerg Strempfer, Steven Kearney, Altaf Khan, Daniela Capatina, R Reininger, D Shu, C Wolford, M Golebiowski, L Rebuffi, X Shi, et al. Possibil- ities at the polar beamline with aps-u. In Journal of Physics: Conference Series , volume 2380, page 012038. IOP Publishing, 2022

    2022

  32. [40]

    Gener- alized perspective on chiral measurements with- out magnetic interactions

    Andres F Ordonez and Olga Smirnova. Gener- alized perspective on chiral measurements with- out magnetic interactions. Physical Review A , 98(6):063428, 2018

    2018

  33. [41]

    Synthetic chiral light for efficient control of chiral light– matter interaction

    David Ayuso, Ofer Neufeld, Andres F Ordonez, Piero Decleva, Gavriel Lerner, Oren Cohen, Misha Ivanov, and Olga Smirnova. Synthetic chiral light for efficient control of chiral light– matter interaction. Nature Photonics, 13(12):866– 871, 2019

    2019

  34. [42]

    Molecu- lar chirality and its monitoring by ultrafast x-ray pulses

    J ´er´emy R Rouxel and Shaul Mukamel. Molecu- lar chirality and its monitoring by ultrafast x-ray pulses. Chemical Reviews , 122(22):16802–16838, 2022

    2022

  35. [43]

    X-ray and optical wave mixing

    Thornton E Glover, DM Fritz, Marco Cammarata, TK Allison, Sinisa Coh, JM Feldkamp, H Lemke, 10 D Zhu, Y Feng, RN Coffee, et al. X-ray and optical wave mixing. Nature, 488(7413):603–608, 2012

    2012

  36. [44]

    X-ray two-photon absorption competing against single and sequential multiphoton processes

    Kenji Tamasaku, Eiji Shigemasa, Yuichi Inubushi, Tetsuo Katayama, Kei Sawada, Hirokatsu Yu- moto, Haruhiko Ohashi, Hidekazu Mimura, Makina Yabashi, Kazuto Yamauchi, et al. X-ray two-photon absorption competing against single and sequential multiphoton processes. Nature Photoni...

    2014

  37. [45]

    X-ray sec- ond harmonic generation

    Sharon Shwartz, Matthias Fuchs, JB Hastings, Y Inubushi, T Ishikawa, T Katayama, DA Reis, T Sato, K Tono, M Yabashi, et al. X-ray sec- ond harmonic generation. Physical review letters, 112(16):163901, 2014

    2014

  38. [46]

    Parametric down-conversion of x rays into the optical regime

    A Schori, C B ¨omer, D Borodin, SP Collins, B Detlefs, M Moretti Sala, S Yudovich, and S Shwartz. Parametric down-conversion of x rays into the optical regime. Physical review letters , 119(25):253902, 2017

    2017

  39. [47]

    Nonlinear op- tical spectroscopy of chiral molecules

    Peer Fischer and Franc ¸ois Hache. Nonlinear op- tical spectroscopy of chiral molecules. Chiral- ity: the pharmacological, biological, and chemical con- sequences of molecular asymmetry , 17(8):421–437, 2005

    2005

  40. [48]

    Femtosecond vibrational sum-frequency genera- tion spectroscopy of chiral molecules in isotropic liquid

    Taegon Lee, Hanju Rhee, and Minhaeng Cho. Femtosecond vibrational sum-frequency genera- tion spectroscopy of chiral molecules in isotropic liquid. The Journal of Physical Chemistry Letters , 9(23):6723–6730, 2018

    2018

  41. [49]

    Manipulating ultrafast even-order nonlinear chiral responses of l-tryptophan by polarization pulse shaping

    J ´er´emy R Rouxel, Yeonsig Nam, Vladimir Y Chernyak, and Shaul Mukamel. Manipulating ultrafast even-order nonlinear chiral responses of l-tryptophan by polarization pulse shaping. Proceedings of the National Academy of Sciences , 121(23):e2402660121, 2024

    2024

  42. [50]

    Coherent optical mixing in optically active liq- uids

    PM Rentzepis, JA Giordmaine, and KW Wecht. Coherent optical mixing in optically active liq- uids. Physical review letters, 16(18):792, 1966

    1966

  43. [51]

    Three-wave mixing in chiral liquids

    Peer Fischer, Diederik S Wiersma, Roberto Righ- ini, Beno ˆıt Champagne, and A David Bucking- ham. Three-wave mixing in chiral liquids. Physi- cal review letters, 85(20):4253, 2000

    2000

  44. [52]

    Sum-frequency generation in chiral liquids near electronic resonance

    MA Belkin, SH Han, X Wei, and YR Shen. Sum-frequency generation in chiral liquids near electronic resonance. Physical review letters , 87(11):113001, 2001

    2001

  45. [53]

    Strong chiral response in non-collinear high harmonic genera- tion driven by purely electric-dipole interactions

    David Ayuso, Andres F Ordonez, Piero Decleva, Misha Ivanov, and Olga Smirnova. Strong chiral response in non-collinear high harmonic genera- tion driven by purely electric-dipole interactions. Optics Express, 30(4):4659–4667, 2022

    2022

  46. [54]

    Amino acids

    A Kleemann, W Leuchtenberger, B Hoppe, and H Tanner. Amino acids. ullmann’s encyclopedia of industrial chemistry, 1985

    1985

  47. [55]

    Stereo- chemistry of terpene derivatives

    Daniel Jan Strub, Lucyna Balcerzak, Maria Niewiadomska, J ´ozef Kula, Magdalena Sikora, Julia Gibka, and Stanisław Lochy ´nski. Stereo- chemistry of terpene derivatives. part 8: synthe- sis of novel terpenoids from (1s, 4r)-and (1r, 4s)- fenchone and their comparative odour ch...

    2014

  48. [56]

    Circular dichro- ism in the photoelectron angular distributions of camphor and fenchone from multiphoton ion- ization with femtosecond laser pulses

    Christian Lux, Matthias Wollenhaupt, Tom Bolze, Qingqing Liang, Jens K ¨ohler, Cristian Sarpe, and Thomas Baumert. Circular dichro- ism in the photoelectron angular distributions of camphor and fenchone from multiphoton ion- ization with femtosecond laser pulses. Ange- wandte ...

    2012

  49. [57]

    X-ray absorption spectroscopy of the chiral molecules fenchone, α-pinene, limonene and carvone in the c1s excitation re- gion

    Christian Ozga, Kari J ¨ank¨al¨a, Philipp Schmidt, Andreas Hans, Philipp Reiß, Arno Ehresmann, and Andr´e Knie. X-ray absorption spectroscopy of the chiral molecules fenchone, α-pinene, limonene and carvone in the c1s excitation re- gion. Journal of Electron Spectroscopy and R...

    2016

  50. [58]

    The opti- cal activity of the disulfide bond in l-cystine and some derivatives of l-cystine

    David L Coleman and Elkan R Blout. The opti- cal activity of the disulfide bond in l-cystine and some derivatives of l-cystine. Journal of the Amer- ican Chemical Society, 90(9):2405–2416, 1968

    1968

  51. [59]

    Molecular quantum electrodynamics: an intro- duction to radiation-molecule interactions

    David Parker Craig and Thiru Thirunamachan- dran. Molecular quantum electrodynamics: an intro- duction to radiation-molecule interactions . Courier Corporation, 1998

    1998

  52. [60]

    Comprehensive Chi- roptical Spectroscopy, Volume 1: Instrumentation, Methodologies, and Theoretical Simulations , vol- ume 1

    Nina Berova, Prasad L Polavarapu, Koji Nakan- ishi, and Robert W Woody. Comprehensive Chi- roptical Spectroscopy, Volume 1: Instrumentation, Methodologies, and Theoretical Simulations , vol- ume 1. John Wiley & Sons, 2011

    2011

  53. [61]

    The- oretical and experimental investigations of the electronic circular dichroism and absorption spectra of bicyclic ketones

    Friedhelm Pulm, J ¨org Schramm, Josef Hormes, Stefan Grimme, and Sigrid D Peyerimhoff. The- oretical and experimental investigations of the electronic circular dichroism and absorption spectra of bicyclic ketones. Chemical Physics , 224(2-3):143–155, 1997

    1997

  54. [62]

    Singh, Nelson De Oliveira, Gus- tavo A

    Dhirendra P . Singh, Nelson De Oliveira, Gus- tavo A. Garcia, Arno Vredenborg, and Ivan Powis. Experimental and theoretical inves- tigation of the 3sp(d) rydberg states of fen- chone by polarized laser resonance-enhanced- multiphoton-ionization and fourier transform vuv absorp...

    2020

  55. [63]

    Molpro: a general-purpose quantum chemistry program package

    Hans-Joachim Werner, Peter J Knowles, Gerald Knizia, Frederick R Manby, and Martin Sch ¨utz. Molpro: a general-purpose quantum chemistry program package. Wiley Interdisciplinary Re- views: Computational Molecular Science , 2(2):242– 253, 2012. 11

    2012

  56. [64]

    R. E. Goetz, T. A. Isaev, B. Nikoobakht, R. Berger, and C. P . Koch. Theoretical description of circu- lar dichroism in photoelectron angular distribu- tions of randomly oriented chiral molecules af- ter multi-photon photoionization. The Journal of Chemical Physics, 146(2):024...

    2017

  57. [65]

    Relativistic douglas–kroll–hess theory

    Markus Reiher. Relativistic douglas–kroll–hess theory. Wiley Interdisciplinary Reviews: Computa- tional Molecular Science, 2(1):139–149, 2012

    2012

  58. [66]

    Innershell ab- sorption spectroscopy of amino acids at all rel- evant absorption edges

    Yan Zubavichus, Andrey Shaporenko, Michael Grunze, and Michael Zharnikov. Innershell ab- sorption spectroscopy of amino acids at all rel- evant absorption edges. The Journal of Physical Chemistry A, 109(32):6998–7000, 2005

    2005

  59. [67]

    A surface me- diated supramolecular chiral phenomenon for recognition of l-and d-cysteine

    Jing Wang, Shuai-Shuai Zhang, Xu Xu, Kai- Xuan Fei, and Yin-Xian Peng. A surface me- diated supramolecular chiral phenomenon for recognition of l-and d-cysteine. Nanomaterials, 8(12):1027, 2018

    2018

  60. [68]

    Biggs, Daniel Healion, Ni- ranjan Govind, and Shaul Mukamel

    Yu Zhang, Jason D. Biggs, Daniel Healion, Ni- ranjan Govind, and Shaul Mukamel. Core and valence excitations in resonant X-ray spec- troscopy using restricted excitation window time-dependent density functional theory. The Journal of Chemical Physics , 137(19):194306, 11 2012

    2012

  61. [69]

    R. Maul, M. Preuss, F. Ortmann, K. Hannewald, and F. Bechstedt. Electronic excitations of glycine, alanine, and cysteine conformers from first-principles calculations. The Journal of Phys- ical Chemistry A, 111(20):4370–4377, 2007. PMID: 17461555

    2007

  62. [70]

    Theoretical study of x-ray circular dichroism of amino acids

    Oleksandr Plashkevych, Vincenzo Carravetta, Olav Vahtras, and Hans ˚Agren. Theoretical study of x-ray circular dichroism of amino acids. Chem- ical Physics, 232(1):49–62, 1998

    1998

  63. [71]

    X-ray cir- cular dichroism signals: a unique probe of local molecular chirality

    Yu Zhang, J ´er´emy R Rouxel, Jochen Autschbach, Niranjan Govind, and Shaul Mukamel. X-ray cir- cular dichroism signals: a unique probe of local molecular chirality. Chemical science , 8(9):5969– 5978, 2017

    2017

  64. [72]

    Resonant x-ray difference fre- quency generation

    Carles Serrat. Resonant x-ray difference fre- quency generation. Journal of Physics B: Atomic, Molecular and Optical Physics, 56(24):245601, 2023

    2023

  65. [73]

    Experimental demonstration of attosecond pump–probe spectroscopy with an x-ray free-electron laser

    Zhaoheng Guo, Taran Driver, Sandra Beauvarlet, David Cesar, Joseph Duris, Paris L Franz, Oliver Alexander, Dorian Bohler, Christoph Bostedt, Vi- tali Averbukh, et al. Experimental demonstration of attosecond pump–probe spectroscopy with an x-ray free-electron laser. Nature Pho...

    2024

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