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Nakamura T, Dangi BB, Wu L, Zhang Y, Schoendorff G, Gordon MS, Yang DS. Spin-orbit coupling of electrons on separate lanthanide atoms of Pr2O2 and its singly charged cation. J Chem Phys 2023; 159:244303. [PMID: 38131482 DOI: 10.1063/5.0185579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 11/27/2023] [Indexed: 12/23/2023] Open
Abstract
Although it plays a critical role in the photophysics and catalysis of lanthanides, spin-orbit coupling of electrons on individual lanthanide atoms in small clusters is not well understood. The major objective of this work is to probe such coupling of the praseodymium (Pr) 4f and 6s electrons in Pr2O2 and Pr2O2+. The approach combines mass-analyzed threshold ionization spectroscopy and spin-orbit multiconfiguration second-order quasi-degenerate perturbation theory. The energies of six ionization transitions are precisely measured; the adiabatic ionization energy of the neutral cluster is 38 045 (5) cm-1. Most of the electronic states involved in these transitions are identified as spin-orbit coupled states consisting of two or more electron spins. The electron configurations of these states are 4f46s2 for the neutral cluster and 4f46s for the singly charged cation, both in planar rhombus-type structures. The spin-orbit splitting due to the coupling of the electrons on the separate Pr atoms is on the order of hundreds of wavenumbers.
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Affiliation(s)
- Taiji Nakamura
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011-3111, USA
- Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
| | - Beni B Dangi
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA
| | - Lu Wu
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA
| | - Yuchen Zhang
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA
| | - George Schoendorff
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011-3111, USA
- Propellants Branch, Rocket Propulsion Division, Aerospace Systems Directorate, Air Force Research Laboratory, AFRL/RQRP, Edwards Air Force Base, California 93524, USA
| | - Mark S Gordon
- Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011-3111, USA
| | - Dong-Sheng Yang
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA
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Wibowo M, Huynh BC, Cheng CY, Irons TJP, Teale AM. Understanding ground and excited-state molecular structure in strong magnetic fields using the maximum overlap method. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2152748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Meilani Wibowo
- School of Chemistry, University of Nottingham, University Park, Nottingham, UK
| | - Bang C. Huynh
- School of Chemistry, University of Nottingham, University Park, Nottingham, UK
| | - Chi Y. Cheng
- School of Chemistry, University of Nottingham, University Park, Nottingham, UK
| | - Tom J. P. Irons
- School of Chemistry, University of Nottingham, University Park, Nottingham, UK
| | - Andrew M. Teale
- School of Chemistry, University of Nottingham, University Park, Nottingham, UK
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, Blindern, Oslo, Norway
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Abou Taka A, Lu SY, Gowland D, Zuehlsdorff TJ, Corzo HH, Pribram-Jones A, Shi L, Hratchian HP, Isborn CM. Comparison of Linear Response Theory, Projected Initial Maximum Overlap Method, and Molecular Dynamics-Based Vibronic Spectra: The Case of Methylene Blue. J Chem Theory Comput 2022; 18:3039-3051. [PMID: 35472264 DOI: 10.1021/acs.jctc.1c01127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The simulation of optical spectra is essential to molecular characterization and, in many cases, critical for interpreting experimental spectra. The most common method for simulating vibronic absorption spectra relies on the geometry optimization and computation of normal modes for ground and excited electronic states. In this report, we show that the utilization of such a procedure within an adiabatic linear response (LR) theory framework may lead to state mixings and a breakdown of the Born-Oppenheimer approximation, resulting in a poor description of absorption spectra. In contrast, computing excited states via a self-consistent field method in conjunction with a maximum overlap model produces states that are not subject to such mixings. We show that this latter method produces vibronic spectra much more aligned with vertical gradient and molecular dynamics (MD) trajectory-based approaches. For the methylene blue chromophore, we compare vibronic absorption spectra computed with the following: an adiabatic Hessian approach with LR theory-optimized structures and normal modes, a vertical gradient procedure, the Hessian and normal modes of maximum overlap method-optimized structures, and excitation energy time-correlation functions generated from an MD trajectory. Because of mixing between the bright S1 and dark S2 surfaces near the S1 minimum, computing the adiabatic Hessian with LR theory and time-dependent density functional theory with the B3LYP density functional predicts a large vibronic shoulder for the absorption spectrum that is not present for any of the other methods. Spectral densities are analyzed and we compare the behavior of the key normal mode that in LR theory strongly couples to the optical excitation while showing S1/S2 state mixings. Overall, our study provides a note of caution in computing vibronic spectra using the excited-state adiabatic Hessian of LR theory-optimized structures and also showcases three alternatives that are less sensitive to adiabatic state mixing effects.
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Affiliation(s)
- Ali Abou Taka
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
| | - Shao-Yu Lu
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
| | - Duncan Gowland
- Department of Physics, King's College London, London WC2R 2LS, United Kingdom
| | - Tim J Zuehlsdorff
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, United States
| | - Hector H Corzo
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
| | - Aurora Pribram-Jones
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
| | - Liang Shi
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
| | - Hrant P Hratchian
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
| | - Christine M Isborn
- Department of Chemistry and Biochemistry, University of California Merced, Merced, California 95343, United States
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Gibbard JA, Verlet JRR. Photoelectron imaging of PtI 2 - and its PtI - photodissociation product. J Chem Phys 2022; 156:134303. [PMID: 35395905 DOI: 10.1063/5.0085610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The photoelectron imaging of PtI2 - is presented over photon energies ranging from hν = 3.2 to 4.5 eV. The electron affinity of PtI2 is found to be 3.4 ± 0.1 eV, and the photoelectron spectrum contains three distinct peaks corresponding to three low-lying neutral states. Using a simple d-block model and the measured photoelectron angular distributions, the three states are tentatively assigned. Photodissociation of PtI2 - is also observed, leading to the formation of I- and of PtI-. The latter allows us to determine the electron affinity of PtI to be 2.35 ± 0.10 eV. The spectrum of PtI- is similarly structured with three peaks which, again, can be tentatively assigned using a similar model that agrees with the photoelectron angular distributions.
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Affiliation(s)
- Jemma A Gibbard
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
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5
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Harb H, Hratchian HP. A Density Functional Theory Investigation of the Reaction of Water with Ce2O-. COMPUT THEOR CHEM 2022. [DOI: 10.1016/j.comptc.2022.113603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Mason JL, Harb H, Abou Taka A, Huizenga CD, Corzo HH, Hratchian HP, Jarrold CC. New Photoelectron-Valence Electron Interactions Evident in the Photoelectron Spectrum of Gd 2O . J Phys Chem A 2021; 125:9892-9903. [PMID: 34730978 DOI: 10.1021/acs.jpca.1c07818] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Evidence of strong photoelectron-valence electron (PEVE) interactions has been observed in the anion photoelectron (PE) spectra of several lanthanide suboxide clusters, which are exceptionally complex from an electronic structure standpoint and are strongly correlated systems. The PE spectrum of Gd2O-, which should have relatively simple electronic structure because of its half-filled 4f subshell, exhibits numerous electronic transitions. The electron affinity determined from the spectrum is 0.26 eV. The intensities of transitions to excited states increase relative to the lower-energy states with lower photon energy, which is consistent with shakeup transitions driven by time-dependent electron-neutral interactions. A group of intense spectral features that lie between electron binding energies of 0.7 and 2.3 eV are assigned to transitions involving detachment of an electron from outer-valence σu and σg orbitals that have large Gd 6s contributions. The spectra show parallel transition manifolds in general, which is consistent with detachment from these orbitals. However, several distinct perpendicular transitions are observed adjacent to several of the vertical transitions. A possible explanation invoking interaction between the ejected electron and the high-spin neutral is proposed. Specifically, the angular momentum of electrons ejected from σu or σg orbitals, which is l = 1, can switch to l = 0, 2 with an associated change in the Ms of the remnant neutral, which is spin-orbit coupling between a free electron and the spin of a neutral.
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Affiliation(s)
- Jarrett L Mason
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Hassan Harb
- Department of Chemistry and Biochemistry, University of California, Merced, 5200 North Lake Road, Merced, California 95343, United States
| | - Ali Abou Taka
- Department of Chemistry and Biochemistry, University of California, Merced, 5200 North Lake Road, Merced, California 95343, United States
| | - Caleb D Huizenga
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Hector H Corzo
- Department of Chemistry and Biochemistry, University of California, Merced, 5200 North Lake Road, Merced, California 95343, United States
| | - Hrant P Hratchian
- Department of Chemistry and Biochemistry, University of California, Merced, 5200 North Lake Road, Merced, California 95343, United States
| | - Caroline Chick Jarrold
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
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Babin MC, DeWitt M, DeVine JA, McDonald DC, Ard SG, Shuman NS, Viggiano AA, Cheng L, Neumark DM. Electronic structure of NdO via slow photoelectron velocity-map imaging spectroscopy of NdO --. J Chem Phys 2021; 155:114305. [PMID: 34551540 DOI: 10.1063/5.0063307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Electronically excited NdO is a possible product of the chemistry associated with the release of Nd into the ionosphere, and emission from these states may contribute to the observations following such experiments. To better characterize the energetics and spectroscopy of NdO, we report a combined experimental and theoretical study using slow photoelectron velocity-map imaging spectroscopy of cryogenically cooled NdO- anions (cryo-SEVI) supplemented by wave function-based quantum-chemical calculations. Using cryo-SEVI, we measure the electron affinity of NdO to be 1.0091(7) eV and resolve numerous transitions to low-lying electronic and vibrational states of NdO that are assigned with the aid of the electronic structure calculations. Additionally, temperature-dependent data suggest contributions from the (2)4.5 state of NdO- residing 2350 cm-1 above the ground anion state. Photodetachment to higher-lying excited states of NdO is also reported, which may help to clarify observations from prior release experiments.
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Affiliation(s)
- Mark C Babin
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
| | - Martin DeWitt
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
| | - Jessalyn A DeVine
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
| | - David C McDonald
- NRC Postdoc at Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, Albuquerque, New Mexico 87117, USA
| | - Shaun G Ard
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, Albuquerque, New Mexico 87117, USA
| | - Nicholas S Shuman
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, Albuquerque, New Mexico 87117, USA
| | - Albert A Viggiano
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, Albuquerque, New Mexico 87117, USA
| | - Lan Cheng
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Daniel M Neumark
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
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Huizenga C, Hratchian HP, Jarrold CC. Lanthanide Oxides: From Diatomics to High-Spin, Strongly Correlated Homo- and Heterometallic Clusters. J Phys Chem A 2021; 125:6315-6331. [PMID: 34265204 DOI: 10.1021/acs.jpca.1c04253] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Small lanthanide (Ln) oxide clusters present both experimental and theoretical challenges because of their partially filled, core-like 4f n orbitals, a feature that results in a plethora of close-lying and fundamentally similar electronic states. These clusters provide a bottom-up approach toward understanding the electronic structure of defective or doped bulk material but also can offer a challenge to the theorists to find a method robust enough to capture electronic structure patterns that emerge from within the 4f n (0 < n < 14) series. In this Feature Article, we explore the electronic structures of small lanthanide oxide clusters that deviate from bulk stoichiometry using anion photoelectron spectroscopy and supporting density functional theory calculations. We will describe the evolution of electronic structure with oxidation and how LnxOy- cluster reactivities can be correlated with specific Ln-local orbital occupancies. These strongly correlated systems offer additional insights into how interactions between electrons and electronically complex neutrals can lead to detachment transitions that lie outside of the sudden one-electron detachment approximation generally assumed in anion photoelectron spectroscopy. With a better understanding of how we can control nominally forbidden transitions to sample an array of spin states, we suggest that more in-depth studies on the magnetic states of these systems can be explored. Extending these studies to other Ln-based materials with hidden magnetic phases, along with sequentially ligated single molecule magnets, could advance current understanding of these systems.
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Affiliation(s)
- Caleb Huizenga
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Hrant P Hratchian
- Department of Chemistry and Chemical Biology, University of California, Merced, 5200 North Lake Road, Merced, California 95343, United States
| | - Caroline Chick Jarrold
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
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Harb H, Hratchian HP. ΔSCF Dyson orbitals and pole strengths from natural ionization orbitals. J Chem Phys 2021; 154:084104. [DOI: 10.1063/5.0040454] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
- Hassan Harb
- Department of Chemistry and Chemical Biology and Center for Chemical Computation and Theory, University of California, Merced, California 95343, USA
| | - Hrant P. Hratchian
- Department of Chemistry and Chemical Biology and Center for Chemical Computation and Theory, University of California, Merced, California 95343, USA
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