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Tygesen AS, Mathiesen NR, Chang JH, García-Lastra JM. Density functional theory study of superoxide ions as impurities in alkali halides. Phys Chem Chem Phys 2020; 22:13378-13389. [DOI: 10.1039/d0cp00719f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An exhaustive mapping of the orientation of the unpaired electron from a superoxide impurity in alkali halides using DFT.
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Affiliation(s)
- Alexander S. Tygesen
- Department of Energy Conversion and Storage
- Technical University of Denmark
- 2800 Kgs. Lyngby
- Denmark
| | - Nicolai R. Mathiesen
- Department of Energy Conversion and Storage
- Technical University of Denmark
- 2800 Kgs. Lyngby
- Denmark
| | - Jin Hyun Chang
- Department of Energy Conversion and Storage
- Technical University of Denmark
- 2800 Kgs. Lyngby
- Denmark
| | - Juan María García-Lastra
- Department of Energy Conversion and Storage
- Technical University of Denmark
- 2800 Kgs. Lyngby
- Denmark
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Oriented Polar Molecules in a Solid Inert-Gas Matrix: A Proposed Method for Measuring the Electric Dipole Moment of the Electron. ATOMS 2018. [DOI: 10.3390/atoms6010003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Tyagi A, Silotia P, Maan A, Prasad V. Adsorbed molecules in external fields: Effect of confining potential. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2016; 169:238-245. [PMID: 27387127 DOI: 10.1016/j.saa.2016.04.052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 04/25/2016] [Accepted: 04/27/2016] [Indexed: 06/06/2023]
Abstract
We study the rotational excitation of a molecule adsorbed on a surface. As is well known the interaction potential between the surface and the molecule can be modeled in number of ways, depending on the molecular structure and the geometry under which the molecule is being adsorbed by the surface. We explore the effect of change of confining potential on the excitation, which is largely controlled by the static electric fields and continuous wave laser fields. We focus on dipolar molecules and hence we restrict ourselves to the first order interaction in field-molecule interaction potential either through permanent dipole moment or/and the molecular polarizability parameter. It is shown that confining potential shapes, strength of the confinement, strongly affect the excitation. We compare our results for different confining potentials.
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Affiliation(s)
- Ashish Tyagi
- Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India.
| | - Poonam Silotia
- Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India.
| | - Anjali Maan
- Department of Physics, Pt. N. R. S. G. C., Maharishi Dayanand University, Rohtak, Haryana, India.
| | - Vinod Prasad
- Department of Physics, Swami Shraddhanand College, University of Delhi, Delhi 110036, India.
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Berg M, Accardi A, Paulus B, Schmidt B. Rotationally adiabatic pair interactions of para- and ortho-hydrogen with the halogen molecules F2, Cl2, and Br2. J Chem Phys 2014; 141:074303. [PMID: 25149782 DOI: 10.1063/1.4892599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The present work is concerned with the weak interactions between hydrogen and halogen molecules, i.e., the interactions of pairs H2-X2 with X = F, Cl, Br, which are dominated by dispersion and quadrupole-quadrupole forces. The global minimum of the four-dimensional (4D) coupled cluster with singles and doubles and perturbative triples (CCSD(T)) pair potentials is always a T shaped structure where H2 acts as the hat of the T, with well depths (De) of 1.3, 2.4, and 3.1 kJ/mol for F2, Cl2, and Br2, respectively. MP2/AVQZ results, in reasonable agreement with CCSD(T) results extrapolated to the basis set limit, are used for detailed scans of the potentials. Due to the large difference in the rotational constants of the monomers, in the adiabatic approximation, one can solve the rotational Schrödinger equation for H2 in the potential of the X2 molecule. This yields effective two-dimensional rotationally adiabatic potential energy surfaces where pH2 and oH2 are point-like particles. These potentials for the H2-X2 complexes have global and local minima for effective linear and T-shaped complexes, respectively, which are separated by 0.4-1.0 kJ/mol, where oH2 binds stronger than pH2 to X2, due to higher alignment to minima structures of the 4D-pair potential. Further, we provide fits of an analytical function to the rotationally adiabatic potentials.
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Affiliation(s)
- Matthias Berg
- Institut für Chemie, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany
| | - Antonio Accardi
- Institut für Chemie, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany
| | - Beate Paulus
- Institut für Chemie, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany
| | - Burkhard Schmidt
- Institut für Mathematik, Freie Universität Berlin, Arnimallee 6, D-14195 Berlin, Germany
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Schmidt B, Friedrich B. Topology of surfaces for molecular Stark energy, alignment, and orientation generated by combined permanent and induced electric dipole interactions. J Chem Phys 2014; 140:064317. [DOI: 10.1063/1.4864465] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Accardi A, Schmidt B. RETRACTED ARTICLE: Quantum effects on translation and rotation of molecular chlorine in solid para-hydrogen. Mol Phys 2013. [DOI: 10.1080/00268976.2013.868086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Antonio Accardi
- Institut für Chemie, Freie Universität Berlin, Berlin, Germany
| | - Burkhard Schmidt
- Institut für Mathematik, Freie Universität Berlin, Berlin, Germany
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Affiliation(s)
- Mikhail Lemeshko
- a ITAMP, Harvard-Smithsonian Center for Astrophysics , Cambridge , MA , 02138 , USA
- b Physics Department , Harvard University , Cambridge , MA , 02138 , USA
- c Kavli Institute for Theoretical Physics , University of California , Santa Barbara , CA , 93106 , USA
| | - Roman V. Krems
- c Kavli Institute for Theoretical Physics , University of California , Santa Barbara , CA , 93106 , USA
- d Department of Chemistry , University of British Columbia , BC V6T 1Z1, Vancouver , Canada
| | - John M. Doyle
- b Physics Department , Harvard University , Cambridge , MA , 02138 , USA
| | - Sabre Kais
- e Departments of Chemistry and Physics , Purdue University , West Lafayette , IN , 47907 , USA
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Fajardo ME, Lindsay CM, Momose T. Crystal field theory analysis of rovibrational spectra of carbon monoxide monomers isolated in solid parahydrogen. J Chem Phys 2009; 130:244508. [DOI: 10.1063/1.3158947] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kiljunen T, Popov E, Kunttu H, Eloranta J. Rotation of methyl radicals in a solid krypton matrix. J Chem Phys 2009; 130:164504. [PMID: 19405591 DOI: 10.1063/1.3122004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Electron spin resonance (ESR) measurements were carried out to study the rotation of methyl radicals (CH(3)) in a solid krypton matrix at 17-31 K temperature range. The radicals were produced by dissociating methane by plasma bursts generated by a focused 193 nm excimer laser radiation during the krypton gas condensation on the substrate. The ESR spectrum exhibits only isotropic features at the temperature range examined, and the intensity ratio between the symmetric (A) and antisymmetric (E) spin state lines exhibits weaker temperature dependence than in a solid argon matrix. However, the general appearance of the methyl radical spectrum depends strongly on temperature due to the pronounced temperature dependency of the E state linewidths. The rotational energy level populations are analyzed based on the static crystal field model, pseudorotating cage model, and quantum chemical calculations for an axially symmetric, planar rotor. Crystal field strength parameter values of -140 cm(-1) in Ar and -240 cm(-1) in Kr match most closely the experimentally observed rotational energy level shifts from the gas phase value. In the alternative model, considering the lattice atom movement in a pseudorotating cage, the effective lowering of the rotational constants B and C to 80%-90% leads to similar effects.
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Affiliation(s)
- Toni Kiljunen
- Department of Chemistry, Nanoscience Center, University of Jyväskylä, P.O. Box 35, FIN 40014, Finland
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Gühr M, Bargheer M, Fushitani M, Kiljunen T, Schwentner N. Ultrafast dynamics of halogens in rare gas solids. Phys Chem Chem Phys 2007; 9:779-801. [PMID: 17287873 DOI: 10.1039/b609058n] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We perform time resolved pump-probe spectroscopy on small halogen molecules ClF, Cl2, Br2, and I2 embedded in rare gas solids (RGS). We find that dissociation, angular depolarization, and the decoherence of the molecule is strongly influenced by the cage structure. The well ordered crystalline environment facilitates the modelling of the experimental angular distribution of the molecular axis after the collision with the rare gas cage. The observation of many subsequent vibrational wave packet oscillations allows the construction of anharmonic potentials and indicate a long vibrational coherence time. We control the vibrational wave packet revivals, thereby gaining information about the vibrational decoherence. The coherence times are remarkable larger when compared to the liquid or high pressure gas phase. This fact is attributed to the highly symmetric molecular environment of the RGS. The decoherence and energy relaxation data agree well with a perturbative model for moderate vibrational excitation and follow a classical model in the strong excitation limit. Furthermore, a wave packet interferometry scheme is applied to deduce electronic coherence times. The positions of those cage atoms, excited by the molecular electronic transitions are modulated by long living coherent phonons of the RGS, which we can probe via the molecular charge transfer states.
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Affiliation(s)
- M Gühr
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195, Berlin, Germany
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