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Pettersson, Lars Gunnar MoodyORCID iD iconorcid.org/0000-0003-1133-9934
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Publications (10 of 163) Show all publications
Moncada, F., Quintero, W., Posada, E., Pettersson, L. G. & Reyes, A. (2024). A nuclear configuration interaction approach to study nuclear spin effects: an application to ortho- and para-3He2@C60. ChemPhysChem, 25(4), Article ID e202300498.
Open this publication in new window or tab >>A nuclear configuration interaction approach to study nuclear spin effects: an application to ortho- and para-3He2@C60
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2024 (English)In: ChemPhysChem, ISSN 1439-4235, E-ISSN 1439-7641, Vol. 25, no 4, article id e202300498Article in journal (Refereed) Published
Abstract [en]

We introduce a non-orthogonal configuration interaction approach to investigate nuclear quantum effects on energies and densities of confined fermionic nuclei. The Hamiltonian employed draws parallels between confined systems and many-electron atoms, where effective non-Coulombic potentials represent the interactions of the trapped particles. One advantage of this method is its generality, as it offers the potential to study the nuclear quantum effects of various confined species affected by effective isotropic or anisotropic potentials. As a first application, we analyze the quantum states of two 3He atoms encapsulated in C60. At the Hartree–Fock level, we observe the breaking of spin and spatial symmetries. To ensure wavefunctions with the correct symmetries, we mix the broken-symmetry Hartree–Fock states within the non-orthogonal configuration interaction expansion. Our proposed approach predicts singly and triply degenerate ground states for the singlet (para-3He2@C60) and triplet (ortho-3He2@C60) nuclear spin configurations, respectively. The ortho-3He2@C60 ground state is 5.69 cm−1 higher in energy than the para-3He2@C60 ground state. The nuclear densities obtained for these states exhibit the icosahedral symmetry of the C60 embedding potential. Importantly, our calculated energies for the lowest 85 states are in close agreement with perturbation theory results based on a harmonic oscillator plus rigid rotor model of 3He2@C60

Keywords
ab initio calculations, fullerenes, isotope effects, nuclear quantum effects, quantum chemistry
National Category
Theoretical Chemistry
Identifiers
urn:nbn:se:su:diva-226128 (URN)10.1002/cphc.202300498 (DOI)001141772000001 ()38055206 (PubMedID)2-s2.0-85182230259 (Scopus ID)
Available from: 2024-02-06 Created: 2024-02-06 Last updated: 2024-02-21Bibliographically approved
Fransson, T. & Pettersson, L. G. M. (2023). Calibrating TDDFT Calculations of the X-ray Emission Spectrum of Liquid Water: The Effects of Hartree-Fock Exchange. Journal of Chemical Theory and Computation, 19(20), 7333-7342
Open this publication in new window or tab >>Calibrating TDDFT Calculations of the X-ray Emission Spectrum of Liquid Water: The Effects of Hartree-Fock Exchange
2023 (English)In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 19, no 20, p. 7333-7342Article in journal (Refereed) Published
Abstract [en]

The structure and dynamics of liquid water continue to be debated, with insight provided by, among others, X-ray emission spectroscopy (XES), which shows a split in the high-energy 1b1 feature. This split is yet to be reproduced by theory, and it remains unclear if these difficulties are related to inaccuracies in dynamics simulations, spectrum calculations, or both. We investigate the performance of different methods for calculating XES of liquid water, focusing on the ability of time-dependent density functional theory (TDDFT) to reproduce reference spectra obtained by high-level coupled cluster and algebraic-diagrammatic construction scheme calculations. A metric for evaluating the agreement between theoretical spectra termed the integrated absolute difference (IAD), which considers the integral of shifted difference spectra, is introduced and used to investigate the performance of different exchange-correlation functionals. We find that computed spectra of symmetric and asymmetric model water structures are strongly and differently influenced by the amount of Hartree-Fock exchange, with best agreement to reference spectra for similar to 40-50%. Lower percentages tend to yield high density of contributing states, resulting in too broad features. The method introduced here is useful also for other spectrum calculations, in particular where the performance for ensembles of structures are evaluated.

Keywords
Chemical calculations, Cluster chemistry, Energy, Time dependant density functional theory, Water
National Category
Theoretical Chemistry Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:su:diva-223185 (URN)10.1021/acs.jctc.3c00728 (DOI)001077682700001 ()37787584 (PubMedID)
Available from: 2023-10-25 Created: 2023-10-25 Last updated: 2023-10-25Bibliographically approved
Takahashi, O. & Pettersson, L. G. (2023). Dynamical and interference effects in X-ray emission spectroscopy of H-bonded water – origin of the split lone-pair peaks. Molecular Physics, 121(7-8), Article ID e2170686.
Open this publication in new window or tab >>Dynamical and interference effects in X-ray emission spectroscopy of H-bonded water – origin of the split lone-pair peaks
2023 (English)In: Molecular Physics, ISSN 0026-8976, E-ISSN 1362-3028, Vol. 121, no 7-8, article id e2170686Article in journal (Refereed) Published
Abstract [en]

We examine the effects of core-hole-induced dynamics and vibrational interference on computed x-ray emission spectra of H-bonded water. Two model pentamers were investigated, tetrahedral and distorted, representing possible local environments in proposed low- and high-density water. Core-hole-induced dynamics were considered in the simulations, and the semi-classical Kramers-Heisenberg (SCKH) scheme to convolute theoretical spectra was applied. We determine the origin of the split two peaks in XES of liquid water to be a combination of the initial H-bonding and subsequent dynamics, where we find faster dynamics for tetrahedrally bonded. We further find that H-bond acceptors move towards the core-excited molecule while donors move away and we analyse the origin of this dynamics in terms of charge-redistributions during the dynamics.

We determine the origin of the split two peaks in X-ray emission spectra of liquid water to be a combination of the initial H-bonding and subsequent dynamics, where we find faster dynamics for tetrahedrally H-bonded water. We further find that H-bond acceptors move towards the core-excited molecule while donors move away and we analyse the origin of this dynamics in terms of charge-redistributions during the dynamics.

Keywords
X-ray emission, water, XES
National Category
Theoretical Chemistry
Identifiers
urn:nbn:se:su:diva-215164 (URN)10.1080/00268976.2023.2170686 (DOI)000925247100001 ()2-s2.0-85147580329 (Scopus ID)
Available from: 2023-03-02 Created: 2023-03-02 Last updated: 2023-10-04Bibliographically approved
Anil, A., White, J., dos Santos, E. C., Terekhina, I., Johnsson, M., Pettersson, L. G., . . . Salazar-Alvarez, G. (2023). Effect of pore mesostructure on the electrooxidation of glycerol on Pt mesoporous catalysts. Journal of Materials Chemistry A, 11(31), 16570-16577
Open this publication in new window or tab >>Effect of pore mesostructure on the electrooxidation of glycerol on Pt mesoporous catalysts
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2023 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 11, no 31, p. 16570-16577Article in journal (Refereed) Published
Abstract [en]

Glycerol is a renewable chemical that has become widely available and inexpensive due to the increased production of biodiesel. Noble metal materials have shown to be effective catalysts for the production of hydrogen and value-added products through the electrooxidation of glycerol. In this work we develop three platinum systems with distinct pore mesostructures, e.g., hierarchical pores (HP), cubic pores (CP) and linear pores (LP); all with high electrochemically active surface area (ECSA). The ECSA-normalized GEOR catalytic activity of the systems follows HPC > LPC > CPC > commercial Pt/C. Regarding the oxidation products, we observe glyceric acid as the main three-carbon product (3C), with oxalic acids as the main two-carbon oxidation product. DFT-based theoretical calculations support the glyceraldehyde route going through tartronic acid towards oxalic acid and also help understanding why the dihydroxyacetone (DHA) route is active despite the absence of DHA amongst the observed oxidation products.

Keywords
electrooxidation, glycerol, mesoporous, platinum, electrocatalysis, hydrogen production
National Category
Chemical Sciences Environmental Engineering Materials Engineering
Identifiers
urn:nbn:se:su:diva-221380 (URN)10.1039/d3ta01738a (DOI)001022934800001 ()2-s2.0-85165460368 (Scopus ID)
Available from: 2023-09-20 Created: 2023-09-20 Last updated: 2023-09-20Bibliographically approved
B. Araujo, R., Rodrigues, G. L., Campos dos Santos, E. & Pettersson, L. G. (2022). Adsorption energies on transition metal surfaces: towards an accurate and balanced description. Nature Communications, 13, Article ID 6853.
Open this publication in new window or tab >>Adsorption energies on transition metal surfaces: towards an accurate and balanced description
2022 (English)In: Nature Communications, E-ISSN 2041-1723, Vol. 13, article id 6853Article in journal (Refereed) Published
Abstract [en]

Density functional theory predictions of binding energies and reaction barriers provide invaluable data for analyzing chemical transformations in heterogeneous catalysis. For high accuracy, effects of band structure and coverage, as well as the local bond strength in both covalent and non-covalent interactions, must be reliably described and much focus has been put on improving functionals to this end. Here, we show that a correction from higher-level calculations on small metal clusters can be applied to improve periodic band structure adsorption energies and barriers. We benchmark against 38 reliable experimental covalent and non-covalent adsorption energies and five activation barriers with mean absolute errors of 2.2 kcal mol−1, 2.7 kcal mol−1, and 1.1 kcal mol−1, respectively, which are lower than for functionals widely used and tested for surface science evaluations, such as BEEF-vdW and RPBE.

National Category
Chemical Sciences
Identifiers
urn:nbn:se:su:diva-211677 (URN)10.1038/s41467-022-34507-y (DOI)000882306500023 ()36369277 (PubMedID)2-s2.0-85141711081 (Scopus ID)
Available from: 2022-11-25 Created: 2022-11-25 Last updated: 2023-03-28Bibliographically approved
Yu, X., B. Araujo, R., Qiu, Z., Campos dos Santos, E., Anil, A., Cornell, A., . . . Johnsson, M. (2022). Hydrogen Evolution Linked to Selective Oxidation of Glycerol over CoMoO4—A Theoretically Predicted Catalyst. Advanced Energy Materials, 12(14), Article ID 2103750.
Open this publication in new window or tab >>Hydrogen Evolution Linked to Selective Oxidation of Glycerol over CoMoO4—A Theoretically Predicted Catalyst
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2022 (English)In: Advanced Energy Materials, ISSN 1614-6832, E-ISSN 1614-6840, Vol. 12, no 14, article id 2103750Article in journal (Refereed) Published
Abstract [en]

Electrochemical valorization of biomass waste (e.g., glycerol) for production of value-added products (such as formic acid) in parallel with hydrogen production holds great potential for developing renewable and clean energy sources. Here, a synergistic effort between theoretical calculations at the atomic level and experiments to predict and validate a promising oxide catalyst for the glycerol oxidation reaction (GOR) are reported, providing a good example of designing novel, cost-effective, and highly efficient electrocatalysts for producing value-added products at the anode and high-purity hydrogen at the cathode. The predicted CoMoO4 catalyst is experimentally validated as a suitable catalyst for GOR and found to perform best among the investigated metal (Mn, Co, Ni) molybdate counterparts. The potential required to reach 10 mA cm−2 is 1.105 V at 60 °C in an electrolyte of 1.0 ᴍ KOH with 0.1 ᴍ glycerol, which is 314 mV lower than for oxygen evolution. The GOR reaction pathway and mechanism based on this CoMoO4 catalyst are revealed by high-performance liquid chromatography and in situ Raman analysis. The coupled quantitative analysis indicates that the CoMoO4 catalyst is highly active toward C—C cleavage, thus presenting a high selectivity (92%) and Faradaic efficiency (90%) for formate production. 

Keywords
cobalt molybdate, formate, glycerol oxidation, hydrogen evolution, in situ Raman
National Category
Chemical Sciences Chemical Engineering
Identifiers
urn:nbn:se:su:diva-202600 (URN)10.1002/aenm.202103750 (DOI)000761234600001 ()2-s2.0-85125261064 (Scopus ID)
Available from: 2022-03-10 Created: 2022-03-10 Last updated: 2022-08-30Bibliographically approved
Shipilin, M., Degerman, D., Lömker, P., Goodwin, C. M., Rodrigues, G. L. S., Wagstaffe, M., . . . Amann, P. (2022). In Situ Surface-Sensitive Investigation of Multiple Carbon Phases on Fe(110) in the Fischer-Tropsch Synthesis. ACS Catalysis, 12(13), 7609-7621
Open this publication in new window or tab >>In Situ Surface-Sensitive Investigation of Multiple Carbon Phases on Fe(110) in the Fischer-Tropsch Synthesis
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2022 (English)In: ACS Catalysis, ISSN 2155-5435, E-ISSN 2155-5435, Vol. 12, no 13, p. 7609-7621Article in journal (Refereed) Published
Abstract [en]

Carbide formation on iron-based catalysts is an integral and, arguably, the most important part of the Fischer–Tropsch synthesis process, converting CO and H2 into synthetic fuels and numerous valuable chemicals. Here, we report an in situ surface-sensitive study of the effect of pressure, temperature, time, and gas feed composition on the growth dynamics of two distinct iron–carbon phases with the octahedral and trigonal prismatic coordination of carbon sites on an Fe(110) single crystal acting as a model catalyst. Using a combination of state-of-the-art X-ray photoelectron spectroscopy at an unprecedentedly high pressure, high-energy surface X-ray diffraction, mass spectrometry, and theoretical calculations, we reveal the details of iron surface carburization and product formation under semirealistic conditions. We provide a detailed insight into the state of the catalyst’s surface in relation to the reaction.

Keywords
Fischer−Tropsch, iron carbide, hydrogenation, carburization, heterogeneous catalysis
National Category
Chemical Sciences
Identifiers
urn:nbn:se:su:diva-207450 (URN)10.1021/acscatal.2c00905 (DOI)000893251300001 ()2-s2.0-85134877369 (Scopus ID)
Available from: 2022-07-26 Created: 2022-07-26 Last updated: 2023-03-23Bibliographically approved
Rodrigues, G. L., Diesen, E., Voss, J., Norman, P. & Pettersson, L. G. (2022). Simulations of x-ray absorption spectra for CO desorbing from Ru(0001) with transition-potential and time-dependent density functional theory approaches. Structural Dynamics, 9(1), Article ID 014101.
Open this publication in new window or tab >>Simulations of x-ray absorption spectra for CO desorbing from Ru(0001) with transition-potential and time-dependent density functional theory approaches
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2022 (English)In: Structural Dynamics, E-ISSN 2329-7778, Vol. 9, no 1, article id 014101Article in journal (Refereed) Published
Abstract [en]

The desorption of a carbon monoxide molecule from a Ru(0001) surface was studied by means of X-ray Absorption Spectra (XAS) computed with Transition Potential (TP-DFT) and Time Dependent (TD-DFT) DFT methods. By unraveling the evolution of the CO electronic structure upon desorption, we observed that at 2.3 Å from the surface, the CO molecule has already predominantly gas-phase character. While C 1s XAS is quite insensitive to changes in the C–O bond length, the O 1s excitation is very sensitive with the π* coming down in energy upon CO bond stretching, which competes with the increase in orbital energy due to the repulsive interaction with the metallic surface. We show in a systematic way that the TP-DFT method can describe the XAS rather well at the endpoints (chemisorbed and gas phase) but is affected by artificial charge transfer and/or incorrect spin treatment in the transition region in cases like CO, where there are low-lying π* orbitals and large exchange interactions between the core 1s and valence-acceptor π* orbitals. As an alternative, we demonstrate by comparing with experimental data that a linear response approach using TD-DFT employing common exchange-correlation functionals and finite-size clusters can yield a good description of the spectral evolution of the 1s → π* transition with correct spin and gas-to-chemisorbed chemical shifts in good agreement with experiment.

National Category
Physical Sciences
Identifiers
urn:nbn:se:su:diva-201884 (URN)10.1063/4.0000135 (DOI)000746515600003 ()35071691 (PubMedID)
Available from: 2022-02-10 Created: 2022-02-10 Last updated: 2023-01-25Bibliographically approved
LaRue, J., Liu, B., Rodrigues, G. L., Liu, C., Torres, J. A., Schreck, S., . . . Nilsson, A. (2022). Symmetry-resolved CO desorption and oxidation dynamics on O/Ru(0001) probed at the C K-edge by ultrafast x-ray spectroscopy. Journal of Chemical Physics, 157(16), Article ID 164705.
Open this publication in new window or tab >>Symmetry-resolved CO desorption and oxidation dynamics on O/Ru(0001) probed at the C K-edge by ultrafast x-ray spectroscopy
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2022 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 157, no 16, article id 164705Article in journal (Refereed) Published
Abstract [en]

We report on carbon monoxide desorption and oxidation induced by 400 nm femtosecond laser excitation on the O/Ru(0001) surface probed by time-resolved x-ray absorption spectroscopy (TR-XAS) at the carbon K-edge. The experiments were performed under constant background pressures of CO (6 × 10−8 Torr) and O2 (3 × 10−8 Torr). Under these conditions, we detect two transient CO species with narrow 2π* peaks, suggesting little 2π* interaction with the surface. Based on polarization measurements, we find that these two species have opposing orientations: (1) CO favoring a more perpendicular orientation and (2) CO favoring a more parallel orientation with respect to the surface. We also directly detect gas-phase CO2 using a mass spectrometer and observe weak signatures of bent adsorbed CO2 at slightly higher x-ray energies than the 2π* region. These results are compared to previously reported TR-XAS results at the O K-edge, where the CO background pressure was three times lower (2 × 10−8 Torr) while maintaining the same O2 pressure. At the lower CO pressure, in the CO 2π* region, we observed adsorbed CO and a distribution of OC–O bond lengths close to the CO oxidation transition state, with little indication of gas-like CO. The shift toward “gas-like” CO species may be explained by the higher CO exposure, which blocks O adsorption, decreasing O coverage and increasing CO coverage. These effects decrease the CO desorption barrier through dipole–dipole interaction while simultaneously increasing the CO oxidation barrier.

National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:su:diva-211588 (URN)10.1063/5.0114399 (DOI)000876502600007 ()36319417 (PubMedID)2-s2.0-85141164489 (Scopus ID)
Available from: 2022-11-23 Created: 2022-11-23 Last updated: 2022-11-28Bibliographically approved
Pettersson, L. G. & Takahashi, O. (2022). The local structure of water from combining diffraction and X-ray spectroscopy. Journal of Non-Crystalline Solids: X, 14, Article ID 100087.
Open this publication in new window or tab >>The local structure of water from combining diffraction and X-ray spectroscopy
2022 (English)In: Journal of Non-Crystalline Solids: X, ISSN 2590-1591, Vol. 14, article id 100087Article in journal (Refereed) Published
Abstract [en]

We build a large (~3400 structures) library of X-ray absorption (XAS) and X-ray emission (XES) spectra computed at high level, which together with their associated structures form the basis for a Monte Carlo fit to the experimental oxygen‑oxygen pair-distribution, XAS and XES spectra for ambient liquid water. The procedure results in weights giving the relative importance of each structure to reproduce the experimental properties. We show that the information content in the X-ray spectroscopic data is strongly complementary to that of X-ray diffraction, and dependent on specific structures that are still consistent with the diffraction data. We fit simultaneously to the X-ray spectroscopy and diffraction experimental data and obtain weights on each structure that give a structural distribution that is consistent with the three experimental datasets. These weights are applied to structural parameters characterizing the local environment of each structure and result in the emergence of more preferred values of these parameters.

National Category
Chemical Sciences
Identifiers
urn:nbn:se:su:diva-206228 (URN)10.1016/j.nocx.2022.100087 (DOI)2-s2.0-85125654466 (Scopus ID)
Available from: 2022-06-14 Created: 2022-06-14 Last updated: 2022-06-14Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0003-1133-9934

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