1
|
Kasapoglu E, Yücel MB, Duque CA. Parabolic-Gaussian Double Quantum Wells under a Nonresonant Intense Laser Field. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:1360. [PMID: 37110945 PMCID: PMC10144647 DOI: 10.3390/nano13081360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 03/29/2023] [Accepted: 04/08/2023] [Indexed: 06/19/2023]
Abstract
In this paper, we investigate the electronic and optical properties of an electron in both symmetric and asymmetric double quantum wells that consist of a harmonic potential with an internal Gaussian barrier under a nonresonant intense laser field. The electronic structure was obtained by using the two-dimensional diagonalization method. To calculate the linear and nonlinear absorption, and refractive index coefficients, a combination of the standard density matrix formalism and the perturbation expansion method was used. The obtained results show that the electronic and thereby optical properties of the considered parabolic-Gaussian double quantum wells could be adjusted to obtain a suitable response to specific aims with parameter alterations such as well and barrier width, well depth, barrier height, and interwell coupling, in addition to the applied nonresonant intense laser field.
Collapse
Affiliation(s)
- Esin Kasapoglu
- Department of Physics, Faculty of Science, Sivas Cumhuriyet University, 58140 Sivas, Türkiye;
| | - Melike Behiye Yücel
- Department of Physics, Faculty of Science, Akdeniz University, 07058 Antalya, Türkiye;
| | - Carlos A. Duque
- Grupo de Materia Condensada-UdeA, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín 050003, Colombia
| |
Collapse
|
2
|
Kasapoglu E, Yücel MB, Duque CA. Harmonic-Gaussian Symmetric and Asymmetric Double Quantum Wells: Magnetic Field Effects. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13050892. [PMID: 36903770 PMCID: PMC10005184 DOI: 10.3390/nano13050892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/16/2023] [Accepted: 02/24/2023] [Indexed: 05/14/2023]
Abstract
In this study, we considered the linear and non-linear optical properties of an electron in both symmetrical and asymmetrical double quantum wells, which consist of the sum of an internal Gaussian barrier and a harmonic potential under an applied magnetic field. Calculations are in the effective mass and parabolic band approximations. We have used the diagonalization method to find eigenvalues and eigenfunctions of the electron confined within the symmetric and asymmetric double well formed by the sum of a parabolic and Gaussian potential. A two-level approach is used in the density matrix expansion to calculate the linear and third-order non-linear optical absorption and refractive index coefficients. The potential model proposed in this study is useful for simulating and manipulating the optical and electronic properties of symmetric and asymmetric double quantum heterostructures, such as double quantum wells and double quantum dots, with controllable coupling and subjected to externally applied magnetic fields.
Collapse
Affiliation(s)
- Esin Kasapoglu
- Physics Department, Science Faculty, Sivas Cumhuriyet University, Sivas 58140, Turkey
| | - Melike Behiye Yücel
- Physics Department, Science Faculty, Akdeniz University, Antalya 07058, Turkey
| | - Carlos A. Duque
- Grupo de Materia Condensada-UdeA, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín AA 1226, Colombia
- Correspondence:
| |
Collapse
|
3
|
Magneto-transport and Thermal properties of TiH diatomic molecule under the influence of magnetic and Aharonov-Bohm (AB) fields. Sci Rep 2022; 12:15430. [PMID: 36104422 PMCID: PMC9474823 DOI: 10.1038/s41598-022-19396-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 08/29/2022] [Indexed: 11/08/2022] Open
Abstract
AbstractIn this study, the effects of Aharonov-Bohm (AB) and magnetic fields on the thermodynamic and magneto-transport properties of TiH diatomic molecule using the Deng-Fan potential as a model are investigated. The functional analysis approach (FAA) is used to solve the Schrodinger equation in the presence of magnetic and AB fields with Deng-Fan potential. The energy equation, as well as the wave function, have been derived. The analytic expressions for the thermo-magnetic and transport properties of the Deng-Fan potential are derived using the energy equation and the partition function. These properties obtained are thoroughly analysed utilising graphical representations. Our analysis shows that the magnetic susceptibility of the TiH exhibits a diamagnetic behaviour, and the specific heat capacity behaviour agrees with the famous Dulong-Petit law when the system is subjected to AB field variations and a fixed magnetic field. Albeit, a slight anomaly is observed in the behaviour of the specific heat capacity. Our findings will be valuable in various fields of physics, including chemical and molecular physics and condensed matter physics, where the derived models could be applied to study other diatomic molecules and quantum dots, respectively.
Collapse
|
4
|
Al-Raeei M. Morse oscillator equation of state: An integral equation theory based with virial expansion and compressibility terms. Heliyon 2022; 8:e09328. [PMID: 35520603 PMCID: PMC9062208 DOI: 10.1016/j.heliyon.2022.e09328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 01/03/2022] [Accepted: 04/21/2022] [Indexed: 11/30/2022] Open
Abstract
A number of interaction energy types are employed in the vibrations studies, especially in the spectroscopic analysis, such as the harmonic oscillator and Morse oscillator. In this research, a derivation of an analytical formula of equation of state of Morse oscillator is considered by employing the approximations used in the simple fluids theory. The compressibility formula of the pressure and the virial expansion formula of the pressure using the solutions of the main equation of the simple fluids theory with one of the approximations of the theory are employed for the purpose of the derivation. The virial coefficients of the total Morse oscillator pressure (the first order one, and the second order one) are found for Morse oscillator with respect to the fractional volume of the components, where we conclude that the first order term is proportional to the absolute temperature directly and depends on the diameter of the particles, while we concluded that the second order coefficient term is more complicated than the first order one with temperature, and also, depends on the three Morse oscillator parameters and the diameter of the particles. Besides, we conclude that the total pressure of Morse oscillator, generally, depends on the minimum energy of the well of Morse oscillator, the width parameter of Morse oscillator, and the equilibrium bond distance of the oscillator, in addition to their dependence on the absolute temperature of the components, and the diameter of the particles. The formula of the Morse oscillator equation of state which is found in this research can be applied to multiple materials described using Morse oscillator such as lots of dimers in the vibrations spectroscopy.
Collapse
Affiliation(s)
- Marwan Al-Raeei
- Faculty of Sciences, Damascus University, Damascus, Syrian Arab Republic
| |
Collapse
|
5
|
Gamper J, Kluibenschedl F, Weiss AKH, Hofer TS. From vibrational spectroscopy and quantum tunnelling to periodic band structures – a self-supervised, all-purpose neural network approach to general quantum problems. Phys Chem Chem Phys 2022; 24:25191-25202. [DOI: 10.1039/d2cp03921d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A general, feedforward neural network strategy for the treatment of a broad range of quantum problems including rotational and vibrational spectroscopy, tunnelling and band structure calculations is presented in this study.
Collapse
Affiliation(s)
- Jakob Gamper
- Theoretical Chemistry, Division, Institute of General, Inorganic and Theoretical Chemistry, Center for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82, A-6020 Innsbruck, Austria
| | - Florian Kluibenschedl
- Theoretical Chemistry, Division, Institute of General, Inorganic and Theoretical Chemistry, Center for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82, A-6020 Innsbruck, Austria
| | - Alexander K. H. Weiss
- Research Institute for Biomedical Aging Research, University of Innsbruck, Rennweg 10, A-6020 Innsbruck, Austria
| | - Thomas S. Hofer
- Theoretical Chemistry, Division, Institute of General, Inorganic and Theoretical Chemistry, Center for Chemistry and Biomedicine, University of Innsbruck, Innrain 80-82, A-6020 Innsbruck, Austria
| |
Collapse
|
6
|
Onate CA, Okon IB, Onyeaju MC, Ebomwonyi O. Vibrational energies of some diatomic molecules for a modified and deformed potential. Sci Rep 2021; 11:22498. [PMID: 34795376 PMCID: PMC8602305 DOI: 10.1038/s41598-021-01998-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 10/29/2021] [Indexed: 11/21/2022] Open
Abstract
A molecular potential model is proposed and the solutions of the radial Schrӧdinger equation in the presence of the proposed potential is obtained. The energy equation and its corresponding radial wave function are calculated using the powerful parametric Nikiforov–Uvarov method. The energies of cesium dimer for different quantum states were numerically obtained for both negative and positive values of the deformed and adjustable parameters. The results for sodium dimer and lithium dimer were calculated numerically using their respective spectroscopic parameters. The calculated values for the three molecules are in excellent agreement with the observed values. Finally, we calculated different expectation values and examined the effects of the deformed and adjustable parameters on the expectation values.
Collapse
Affiliation(s)
- C A Onate
- Physics Programme, Department of Physical Sciences, Landmark University, Omu-Aran, Nigeria. .,Landmark University SDG 4 (Quality Education), Omu-Aran, Nigeria.
| | - I B Okon
- Theoretical Physics Group, Department of Physics, University of Uyo, Uyo, Nigeria
| | - M C Onyeaju
- Theoretical Physics Group, Department of Physics, University of Port Harcourt, P.M.B. 5323 Choba, Port Harcourt, Nigeria
| | - O Ebomwonyi
- Department of Physics, University of Benin, Benin City, Nigeria
| |
Collapse
|
7
|
Bound-state solutions and thermal properties of the modified Tietz-Hua potential. Sci Rep 2021; 11:2129. [PMID: 33483571 PMCID: PMC7822887 DOI: 10.1038/s41598-021-81428-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/05/2021] [Indexed: 11/25/2022] Open
Abstract
An approximate solutions of the radial Schrödinger equation was obtained under a modified Tietz–Hua potential via supersymmetric approach. The effect of the modified parameter and optimization parameter respectively on energy eigenvalues were graphically and numerically examined. The comparison of the energy eigenvalues of modified Tietz–Hua potential and the actual Tietz–Hua potential were examined. The ro-vibrational energy of four molecules were also presented numerically. The thermal properties of the modified Tietz–Hua potential were calculated and the effect of temperature on each of the thermal property were examined under hydrogen fluoride, hydrogen molecule and carbon (ii) oxide. The study reveals that for a very small value of the modified parameter, the energy eigenvalues of the modified Tietz–Hua potential and that of the actual Tietz–Hua potential are equivalent. Finally, the vibrational energies for Cesium molecule was calculated and compared with the observed value. The calculated results were found to be in good agreement with the observed value.
Collapse
|
8
|
Pingak RK, Johannes AZ, Ngara ZS, Bukit M, Nitti F, Tambaru D, Ndii MZ. Accuracy of Morse and Morse-like oscillators for diatomic molecular interaction: A comparative study. RESULTS IN CHEMISTRY 2021. [DOI: 10.1016/j.rechem.2021.100204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
|
9
|
Omugbe E, Osafile OE, Okon IB, Onyeaju MC. Energy Spectrum and the properties of the Schiöberg potential using the WKB approximation approach. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1818860] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- E. Omugbe
- Department of Physics, Federal University of Petroleum Resources, Effurun, Nigeria
| | - O. E. Osafile
- Department of Physics, Federal University of Petroleum Resources, Effurun, Nigeria
| | - I. B. Okon
- Theoretical Physics Group, Department of Physics, University of Uyo, Uyo, Nigeria
| | - M. C. Onyeaju
- Theoretical Physics Group, Department of Physics, University of Port Harcourt, Port Harcourt, Nigeria
| |
Collapse
|
10
|
Horchani R, Al-Kindi N, Jelassi H. Ro-vibrational energies of caesium molecules with the Tietz-Hua oscillator. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1812746] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Ridha Horchani
- Department of Physics, College of Science, Sultan Qaboos University, Muscat, Sultanate of Oman
| | - Noor Al-Kindi
- Department of Physics, College of Science, Sultan Qaboos University, Muscat, Sultanate of Oman
| | - Haikel Jelassi
- Department of Physics, College of Science, Sultan Qaboos University, Muscat, Sultanate of Oman
- Laboratory on Energy and Matter for Nuclear Sciences Development (LR16CNSTN02), National Center for Nuclear Sciences and Technologies, Ariana, Tunisia
| |
Collapse
|
11
|
Al-Raeei M, El-Daher MS. An algorithm for fractional Schrödinger equation in case of Morse potential. AIP ADVANCES 2020. [DOI: 10.1063/1.5113593] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Marwan Al-Raeei
- Faculty of Sciences, Damascus University, Damascus, Syrian Arab Republic
| | - Moustafa Sayem El-Daher
- Faculty of Informatics and Communications, Arab International University, Daraa, Syrian Arab Republic
- Higher Institute of Laser Applications and Researches, Damascus University, Damascus, Syrian Arab Republic
| |
Collapse
|
12
|
Hansen AS, Vogt E, Kjaergaard HG. Gibbs energy of complex formation – combining infrared spectroscopy and vibrational theory. INT REV PHYS CHEM 2019. [DOI: 10.1080/0144235x.2019.1608689] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Anne S. Hansen
- Department of Chemistry, University of Copenhagen, Copenhagen Ø, Denmark
| | - Emil Vogt
- Department of Chemistry, University of Copenhagen, Copenhagen Ø, Denmark
| | | |
Collapse
|
13
|
Affiliation(s)
- Emil Vogt
- Department of Chemistry, University of Copenhagen, Copenhagen Ø, Denmark
| | - Daniel S. Sage
- Department of Mathematics, Louisiana State University, Baton Rouge, LA, USA
| | | |
Collapse
|
14
|
|
15
|
Effect of dissociation energy on Shannon and Rényi entropies. KARBALA INTERNATIONAL JOURNAL OF MODERN SCIENCE 2018. [DOI: 10.1016/j.kijoms.2017.12.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
|
16
|
Tang HM, Liang GC, Zhang LH, Zhao F, Jia CS. Diatomic molecule energies of the modified Rosen−Morse potential energy model. CAN J CHEM 2014. [DOI: 10.1139/cjc-2013-0563] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We solve the Schrödinger equation with the modified Rosen−Morse empirical potential model to obtain rotation-vibrational energy spectra and unnormalized radial wave functions. The vibrational energy levels calculated with the modified Rosen−Morse potential model for the 61Πu state of the 7Li2 molecule and the X3Π state of the SiC radical are in better agreement with the Rydberg−Klein−Rees data than the predictions of the Morse potential model.
Collapse
Affiliation(s)
- Hong-Ming Tang
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
- School of Resources and Environment Engineering, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
| | - Guang-Chuan Liang
- School of Petroleum Engineering, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
| | - Lie-Hui Zhang
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
| | - Feng Zhao
- School of Resources and Environment Engineering, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
| | - Chun-Sheng Jia
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
| |
Collapse
|
17
|
Tang HM, Liang GC, Zhang LH, Zhao F, Jia CS. Molecular energies of the improved Tietz potential energy model. CAN J CHEM 2014. [DOI: 10.1139/cjc-2013-0466] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We solve the Schrödinger equation with the improved Tietz empirical potential energy model. The rotation-vibrational energy spectra and the unnormalized radial wave functions have been obtained. The vibrational energy levels predicted by using the improved Tietz potential model for the 51Δg state and C1Πu state of the Na2 molecule are in good agreement with the experimental Rydberg−Klein−Rees data.
Collapse
Affiliation(s)
- Hong-Ming Tang
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
- School of Resources and Environment Engineering, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
| | - Guang-Chuan Liang
- School of Petroleum Engineering, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
| | - Lie-Hui Zhang
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
| | - Feng Zhao
- School of Resources and Environment Engineering, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
| | - Chun-Sheng Jia
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
| |
Collapse
|
18
|
Abstract
We solve the Schrödinger equation with the improved Rosen−Morse empirical potential energy model. The rotation-vibrational energy spectra and the unnormalized radial wave functions have been obtained. The interaction potential energy curves for the 33Σg+ state of the Cs2 molecule and the 51Δg state of the Na2 molecule are modeled by employing the improved Rosen−Morse potential and the Morse potential. Favourable agreement for the improved Rosen−Morse potential is found in comparing with the Rydberg−Klein−Rees potential. The vibrational energy levels predicted by using the improved Rosen−Morse potential for the 33Σg+ state of Cs2 and the 51Δg state of Na2 are in better agreement with the Rydberg−Klein−Rees data than the predictions of the Morse potential.
Collapse
Affiliation(s)
- Jian-Yi Liu
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
| | - Xue-Tao Hu
- School of Petroleum Engineering, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
| | - Chun-Sheng Jia
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, People’s Republic of China
| |
Collapse
|
19
|
|
20
|
Medvedev ES. Towards understanding the nature of the intensities of overtone vibrational transitions. J Chem Phys 2012; 137:174307. [DOI: 10.1063/1.4761930] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
21
|
Hazra MK, Kuang X, Sinha A. Influence of Intramolecular Hydrogen Bonding on OH-Stretching Overtone Intensities and Band Positions in Peroxyacetic Acid. J Phys Chem A 2011; 116:5784-95. [DOI: 10.1021/jp206637t] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Montu K. Hazra
- Department of Chemistry and Biochemistry, University of California, San Diego La Jolla, California 92093-0314, United States
| | | | - Amitabha Sinha
- Department of Chemistry and Biochemistry, University of California, San Diego La Jolla, California 92093-0314, United States
| |
Collapse
|
22
|
Perez-Delgado Y, Manzanares CE. Cavity Ring Down and Fourier Transform Infrared Spectroscopy at Low Temperatures (84−297 K): Fermi Resonance and Intensities of the C−H Fundamental and Overtone (Δυ = 1−6) Transitions of CHD 3. J Phys Chem A 2010; 114:7918-27. [DOI: 10.1021/jp105382p] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Yasnahir Perez-Delgado
- Department of Chemistry & Biochemistry, Baylor University, 101 Bagby Avenue, Baylor Sciences Building E-216, Waco, Texas 76706
| | - Carlos E. Manzanares
- Department of Chemistry & Biochemistry, Baylor University, 101 Bagby Avenue, Baylor Sciences Building E-216, Waco, Texas 76706
| |
Collapse
|
23
|
Rong Z, Sage ML. Displacement matrix elements of Deng-Fan oscillators. Interdiscip Sci 2010; 1:163-7. [PMID: 20640833 DOI: 10.1007/s12539-009-0030-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2008] [Revised: 01/14/2009] [Accepted: 02/01/2009] [Indexed: 11/29/2022]
Abstract
Analytic expressions for matrix elements of integral powers of the displacement of the coordinate from equilibrium for the Deng-Fan oscillator have been derived. A comparison is made with the corresponding matrix elements for the Morse oscillator. These matrix elements are useful in high overtone spectroscopy and in models for DNA melting.
Collapse
Affiliation(s)
- Zimei Rong
- Department of Chemistry and Biochemistry, University of Guelph, Guelph, Ontario, N1G 2W1, Canada.
| | | |
Collapse
|
24
|
Johannissen LO, Irebo T, Sjödin M, Johansson O, Hammarström L. The Kinetic Effect of Internal Hydrogen Bonds on Proton-Coupled Electron Transfer from Phenols: A Theoretical Analysis with Modeling of Experimental Data. J Phys Chem B 2009; 113:16214-25. [DOI: 10.1021/jp9048633] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Linus O. Johannissen
- Department of Photochemistry and Molecular Science, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden
| | - Tania Irebo
- Department of Photochemistry and Molecular Science, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden
| | - Martin Sjödin
- Department of Photochemistry and Molecular Science, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden
| | - Olof Johansson
- Department of Photochemistry and Molecular Science, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden
| | - Leif Hammarström
- Department of Photochemistry and Molecular Science, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden
| |
Collapse
|
25
|
Meyer MP, Klinman JP. Modeling temperature dependent kinetic isotope effects for hydrogen transfer in a series of soybean lipoxygenase mutants: The effect of anharmonicity upon transfer distance. Chem Phys 2005; 319:283-296. [PMID: 21132078 PMCID: PMC2995544 DOI: 10.1016/j.chemphys.2005.05.017] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Soybean lipoxygenase-1 (SLO) catalyzes the oxidation of linoleic acid. The rate-limiting step in this transformation is the net abstraction of the pro-S hydrogen atom from the center of the 1,5-pentadienyl moiety in linoleic acid. The large deuterium kinetic isotope effect (KIE) for this step appears in the first order rate constant ((D)k(cat) = 81 ± 5 at T = 25 °C). Furthermore, the KIE and the rate for protium abstraction are weakly temperature dependent (E(A,D) - E(A,H) = 0.9 ± 0.2 kcal/mol and E(A,H) = 2.1 ± 0.2 kcal/mol, respectively). Mutations at a hydrophobic site about 13 Å from the active site Fe(III), Ile(553), induce a marked temperature dependence that varies roughly in accordance with the degree to which the residue is changed in bulk from the wild type Ile. While the temperature dependence for these mutants varies from the wild type enzyme, the magnitude of the KIE at 25 °C is on the same order of magnitude. A hydrogen tunneling model [Kuznetsov, A.M., Ulstrup, J. Can. J. Chem. 77 (1999) 1085-1096] is utilized to model the KIE temperature profiles for the wild type SLO and each Ile(553) mutant. Hydrogenic wavefunctions are modeled using harmonic oscillators and Morse oscillators in order to explore the effects of anharmonicity upon computed kinetic observables used to characterize this hydrogen transfer.
Collapse
Affiliation(s)
- Matthew P. Meyer
- Department of Chemistry and Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Judith P. Klinman
- Department of Chemistry and Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| |
Collapse
|
26
|
Rong Z, Henry BR, Robinson TW, Kjaergaard HG. Absolute Intensities of CH Stretching Overtones in Alkenes. J Phys Chem A 2005; 109:1033-41. [PMID: 16833411 DOI: 10.1021/jp040639f] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have measured the CH stretching vibrational spectrum of ethene gas in the regions corresponding to 1-5 quanta in the CH stretching vibration with Fourier transform infrared and conventional absorption spectroscopy and have determined the corresponding oscillator strengths. We have calculated the CH stretching vibrational oscillator strengths for a series of alkenes: ethene, propene, 1,3-butadiene, cis-2-butene, and trans-2-butene. The CH stretching intensities are calculated with a simple Morse oscillator local mode model for CH groups and with the harmonically coupled anharmonic oscillator local mode model for CH2 and CH3 groups. The local mode parameters, frequencies, and anharmonicities are obtained from experiments. The harmonic coupling coefficients and the dipole moment functions are calculated with a range of ab initio methods. These include self-consistent-field Hartree-Fock, density functional, correlated, and multireference theories, combined with basis sets ranging from double- to quadruple-zeta quality augmented with polarization and diffuse functions. Variation in calculated oscillator strengths with the choice of ab initio method is systematically studied and compared with observed intensities. From this comparison between the calculated and observed values, we can quantitatively understand the relative usefulness of various ab initio dipole moment functions in calculations of vibrational oscillator strength for alkenes.
Collapse
Affiliation(s)
- Zimei Rong
- Department of Chemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | | | | | | |
Collapse
|
27
|
|
28
|
Fry JL, Nizkorodov SA, Okumura M, Roehl CM, Francisco JS, Wennberg PO. Cis-cis and trans-perp HOONO: Action spectroscopy and isomerization kinetics. J Chem Phys 2004; 121:1432-48. [PMID: 15260688 DOI: 10.1063/1.1760714] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The weakly bound HOONO product of the OH+NO2+M reaction is studied using the vibrational predissociation that follows excitation of the first OH overtone (2nu1). We observe formation of both cis-cis and trans-perp conformers of HOONO. The trans-perp HOONO 2nu1 band is observed under thermal (223-238 K) conditions at 6971 cm(-1). We assign the previously published (warmer temperature) HOONO spectrum to the 2nu1 band at 6365 cm(-1) and 2nu1-containing combination bands of the cis-cis conformer of HOONO. The band shape of the trans-perp HOONO spectrum is in excellent agreement with the predicted rotational contour based on previous experimental and theoretical results, but the apparent origin of the cis-cis HOONO spectrum at 6365 cm(-1) is featureless and significantly broader, suggesting more rapid intramolecular vibrational redistribution or predissociation in the latter isomer. The thermally less stable trans-perp HOONO isomerizes rapidly to cis-cis HOONO with an experimentally determined lifetime of 39 ms at 233 K at 13 hPa (in a buffer gas of predominantly Ar). The temperature dependence of the trans-perp HOONO lifetime in the range 223-238 K yields an isomerization barrier of 33+/-12 kJ/mol. New ab initio calculations of the structure and vibrational mode frequencies of the transition state perp-perp HOONO are performed using the coupled cluster singles and doubles with perturbative triples [CCSD(T)] model, using a correlation consistent polarized triple zeta basis set (cc-pVTZ). The energetics of cis-cis, trans-perp, and perp-perp HOONO are also calculated at this level [CCSD(T)/cc-pVTZ] and with a quadruple zeta basis set using the structure determined at the triple zeta basis set [CCSD(T)/cc-pVQZ//CCSD(T)/cc-pVTZ]. These calculations predict that the anti form of perp-perp HOONO has an energy of DeltaE0=42.4 kJ/mol above trans-perp HOONO, corresponding to an activation enthalpy of DeltaH298 (double dagger 0)=41.1 kJ/mol. These results are in good agreement with statistical simulations based on a model developed by Golden, Barker, and Lohr. The simulated isomerization rates match the observed decay rates when modeled with a trans-perp to cis-cis HOONO isomerization barrier of 40.8 kJ/mol and a strong collision model. The quantum yield of cis-cis HOONO dissociation to OH and NO2 is also calculated as a function of photon excitation energy in the range 3500-7500 cm(-1), assuming D0=83 kJ/mol. The quantum yield is predicted to vary from 0.15 to 1 over the observed spectrum at 298 K, leading to band intensities in the action spectrum that are highly temperature dependent; however, the observed relative band strengths in the cis-cis HOONO spectrum do not change substantially with temperature over the range 193-273 K. Semiempirical calculations of the oscillator strengths for 2nu1(cis-cis HOONO) and 2nu1(trans-perp HOONO) are performed using (1) a one-dimensional anharmonic model and (2) a Morse oscillator model for the OH stretch, and ab initio dipole moment functions calculated using Becke, Lee, Yang, and Parr density functional theory (B3LYP), Møller-Plesset pertubation theory truncated at the second and third order (MP2 and MP3), and quadratic configuration interaction theory using single and double excitations (QCISD). The QCISD level calculated ratio of 2nu1 oscillator strengths of trans-perp to cis-cis HOONO is 3.7:1. The observed intensities indicate that the concentration of trans-perp HOONO early in the OH+NO2 reaction is significantly greater than predicted by a Boltzmann distribution, consistent with statistical predictions of high initial yields of trans-perp HOONO from the OH+NO2+M reaction. In the atmosphere, trans-perp HOONO will isomerize nearly instantaneously to cis-cis HOONO. Loss of HOONO via photodissociation in the near-IR limits the lifetime of cis-cis HOONO during daylight to less than 45 h, other loss mechanisms will reduce the lifetime further.
Collapse
Affiliation(s)
- Juliane L Fry
- Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, USA.
| | | | | | | | | | | |
Collapse
|