Molecular structure retrieval directly from laboratory-frame photoelectron spectra in laser-induced electron diffraction

Ubiquitous to most molecular scattering methods is the challenge to retrieve bond distance and angle from the scattering signals since this requires convergence of pattern matching algorithms or fitting methods. This problem is typically exacerbated when imaging larger molecules or for dynamic systems with little a priori knowledge. Here, we employ laser- induced electron diffraction (LIED) which is a powerful means to determine the precise atomic configuration of an isolated gas-phase molecule with picometre spatial and attose- cond temporal precision. We introduce a simple molecular retrieval method, which is based only on the identification of critical points in the oscillating molecular interference scattering signal that is extracted directly from the laboratory-frame photoelectron spectrum. The method is compared with a Fourier-based retrieval method, and we show that both methods correctly retrieve the asymmetrically stretched and bent field-dressed configuration of the asymmetric top molecule carbonyl sulfide (OCS), which is confirmed by our quantum- classical calculations.
J.B. and group acknowledge financial support from the European Research Council for ERC Advanced Grant “TRANSFORMER” (788218), ERC Proof of Concept Grant “miniX” (840010), FET-OPEN “PETACom” (829153), FET-OPEN “OPTOlogic” (899794), Laserlab- Europe (EU-H2020 654148), MINECO for Plan Nacional FIS2017-89536-P; AGAUR for 2017 SGR 1639, MINECO for “Severo Ochoa” (SEV-2015-0522), Fundació Cellex Barce- lona, CERCA Programme/Generalitat de Catalunya, the Polish National Science Center within the project Symfonia, 2016/20/W/ST4/00314, and the Alexander von Humboldt Foundation for the Friedrich Wilhelm Bessel Prize. J.B. and K.A. acknowledge the Polish National Science Center within the project Symfonia, 2016/20/W/ST4/00314, B.B. acknowledges Severo Ochoa” (SEV-2015-0522), and A.S. acknowledges funding from the Marie Sklodowska-Curie grant agreement No. 641272. S.J.W. and C.D.L. are supported in part by Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U. S. Department of Energy under Grant No. DE-FG02- 86ER13491. M.R. and S.G. highly acknowledges support from the European Research Council (ERC) for the ERC Consolidator Grant QUEM-CHEM (772676).
Peer Reviewed
Postprint (published version)