1
|
Yang Z, Wang S, Yuan J, Chen M. Neural network potential energy surface and dynamical isotope effects for the N+(3P) + H2 → NH+ + H reaction. Phys Chem Chem Phys 2019; 21:22203-22214. [DOI: 10.1039/c9cp02798j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dynamical isotope effects are calculated for the N+(3P) + H2 → NH+ + H reaction on a new neural network potential energy surface.
Collapse
Affiliation(s)
- Zijiang Yang
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education)
- School of Physics
- Dalian University of Technology
- Dalian 116024
- P. R. China
| | - Shufen Wang
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education)
- School of Physics
- Dalian University of Technology
- Dalian 116024
- P. R. China
| | - Jiuchuang Yuan
- State Key Laboratory of Molecular Reaction Dynamics
- Dalian Institute of Chemical Physics
- Chinese Academy of Science
- Dalian 116023
- P. R. China
| | - Maodu Chen
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education)
- School of Physics
- Dalian University of Technology
- Dalian 116024
- P. R. China
| |
Collapse
|
2
|
Zhang QQ, Yang CL, Wang MS, Ma XG, Liu WW. Spectroscopic parameters of the low-lying electronic states and laser cooling feasibility of NH + cation and NH - anion. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 185:365-370. [PMID: 28601040 DOI: 10.1016/j.saa.2017.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 06/02/2017] [Indexed: 06/07/2023]
Abstract
The potential energy curves and transition dipole moments of 12Σ+, 22Σ+, 12Π and 22Π states of NH+ cation and NH- anion are calculated by using multi-reference configuration interaction method and large all-electron basis sets. Based on the obtained potential energy curves, the rotational and vibrational energy levels of the states are obtained by solving the Schrödinger equation of nuclear movement. The calculated spectroscopic parameters for NH+ cation and NH- anion are in good agreement with available theoretical and experimental results. The spin orbit coupling effect of the 2Π states for both NH+ cation and NH- anion are calculated. The feasibility of laser cooling of the two molecules is examined by using the results of the molecular structure and spectroscopy. The highly diagonal Franck-Condon factors for the 12Π (v″=0)↔12Σ+ (v'=0) transition of NH+ and NH- are 0.821 and 0.999, while the radiative lifetimes of the 12Σ+ (v'=0) state for the two molecules are 384ns and 52.4ns, respectively. The results indicate that NH+ cation and NH- anion are good candidate molecules for laser cooling. The cooling scheme via Sisyphus process for the NH+ cation and NH- anion are proposed in the paper. The laser wavelengths for the close cycles of the absorption and radiation are also determined. Unfortunately, the potential energy curve of the ground state of the neutral NH molecule shows that the auto-detachment of NH- anion is possible, implying the optical scheme of laser cooling for NH- anion is not easy to achieve in the experiment although it has larger Franck-Condon factor.
Collapse
Affiliation(s)
- Qing-Qing Zhang
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, People's Republic of China
| | - Chuan-Lu Yang
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, People's Republic of China.
| | - Mei-Shan Wang
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, People's Republic of China
| | - Xiao-Guang Ma
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, People's Republic of China
| | - Wen-Wang Liu
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, People's Republic of China
| |
Collapse
|
3
|
Koput J. Ab initio ground-state potential energy function and vibration-rotation energy levels of imidogen, NH. J Comput Chem 2015; 36:1286-94. [PMID: 25920622 DOI: 10.1002/jcc.23931] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 04/07/2015] [Accepted: 04/10/2015] [Indexed: 12/18/2022]
Abstract
The accurate ground-state potential energy function of imidogen, NH, has been determined from ab initio calculations using the multireference averaged coupled-pair functional (MR-ACPF) method in conjunction with the correlation-consistent core-valence basis sets up to octuple-zeta quality. The importance of several effects, including electron correlation beyond the MR-ACPF level of approximation, the scalar relativistic, adiabatic, and nonadiabatic corrections were discussed. Along with the large one-particle basis set, all of these effects were found to be crucial to attain "spectroscopic" accuracy of the theoretical predictions of vibration-rotation energy levels of NH.
Collapse
Affiliation(s)
- Jacek Koput
- Department of Chemistry, Adam Mickiewicz University, 61-614, Poznań, Poland
| |
Collapse
|
4
|
Li X, Zhang X, Yan B. Ab initio study on the low-lying excited states of gas-phase PH(+) cation including spin-orbit coupling. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 142:1-7. [PMID: 25688687 DOI: 10.1016/j.saa.2015.01.070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 01/18/2015] [Accepted: 01/28/2015] [Indexed: 06/04/2023]
Abstract
Ab initio calculations have been performed on the low-lying excited and ground states of PH(+). The potential energy curves (PECs) of the Λ-S states were calculated with multi-reference configuration interaction (MRCI) method along with the basis sets at 5-ξ level. In order to improve the PECs, the Davidson(+Q) correction and the Scalar relativistic effect are included. The corresponding spectroscopic constants were determined and good agreements with the available measurement were found. The interactions of the A(2)Δ-(4)Π and 1(2)Σ(+)-(4)Π by the spin-orbit coupling (SOC) effect were well described by the spin-orbit matrix elements. The SOC effect makes the original 8 Λ-S states split into 15Ω states. The Ω=1/2 state generated from the X(2)Π state is confirmed to the ground Ω state. And the SOC splitting for the X(2)Π is calculated to be 294cm(-1). The SOC effect has large effect on the PECs of the A(2)Δ and 1(2)Σ(+) states, leading to much more shallow potential wells as well as potential barriers. The analysis of the wavefunction for the Ω states shows that the strong spin-orbit interaction exists near the crossing points of the PECs for the Λ-S states. The transition dipole moments (TDMs) of transitions A(2)Δ-X(2)Π and 1(2)Σ(-)-X(2)Π are evaluated with the MRCI wavefunction. Based on the TDMs along with the calculated Franck-Condon factors, the radiative lifetimes for the selected vibrational levels of A(2)Δ and 1(2)Σ(-) states are predicted at the microseconds (μs). Good agreement with the measurement shows that the lowest vibrational level for A(2)Δ state is almost uninfluenced by the perturbation via the SOC effect.
Collapse
Affiliation(s)
- Xia Li
- Hospital Affiliated of Changchun University of Chinese Medicine, Changchun 130021, China
| | - Xiaomei Zhang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China; Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012, China
| | - Bing Yan
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China; Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy (Jilin University), Changchun 130012, China.
| |
Collapse
|
5
|
Deppe J, Friedrichs G, Ibrahim A, Römming HJ, Wagner HG. The Thermal Decomposition of NH2and NH Radicals. ACTA ACUST UNITED AC 2014. [DOI: 10.1002/bbpc.199800016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
6
|
|
7
|
Frankcombe TJ, Nyman G. Statistical modelling of NH+/ND+ + H2/HD/D2 branching ratios. Phys Chem Chem Phys 2008; 10:3000-13. [DOI: 10.1039/b801384e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
|
8
|
Owono Owono LC, Jaidane N, Kwato Njock MG, Ben Lakhdar Z. Theoretical investigation of excited and Rydberg states of imidogen radical NH: Potential energy curves, spectroscopic constants, and dipole moment functions. J Chem Phys 2007; 126:244302. [PMID: 17614544 DOI: 10.1063/1.2741260] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
A search is conducted for the calculation of potential energy curves (PECs), spectroscopic constants, and dipole moment functions for excited and Rydberg states of imidogen radical NH, with a particular emphasis on the Rydberg states arising from 3s configuration of nitrogen and 2s and 2p configurations of hydrogen. A range of about 11 eV above the electronic ground state X (3)Sigma- atomic separation limit which corresponds to the first eight asymptotes of dissociation is spanned. Computations are carried out at the internally contracted multireference singles plus doubles configuration interaction level of theory, including the Davidson correction to account for quadruple excitations. The Gaussian basis set used has been modified from a standard basis to give a balanced description of valence-Rydberg interactions. States of (1)Sigma-, (1)Pi, (1)Delta, (3)Sigma-, (3)Pi, (3)Delta, and (5)Sigma- symmetries are computed accurately in the range of energy investigated. PECs of the three lowest (5)Pi states are obtained for the first time. Our spectroscopic constants show good agreement with experimental data in comparison with other theoretical studies reported in the literature. A discussion on the variations of dipole moment functions helps to understand the strong interactions between excited and Rydberg states as well as the avoided crossings. The present study may be of great practical interest for investigations in astrophysical research as well as in laboratory experiments.
Collapse
Affiliation(s)
- L C Owono Owono
- Département de Physique, Ecole Normale Supérieure, Université de Yaoundé I, Boîte Postale 47, Yaoundé, Cameroun.
| | | | | | | |
Collapse
|
9
|
|
10
|
Kamiya M, Hirata S. Higher-order equation-of-motion coupled-cluster methods for ionization processes. J Chem Phys 2006; 125:074111. [PMID: 16942326 DOI: 10.1063/1.2244570] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Compact algebraic equations defining the equation-of-motion coupled-cluster (EOM-CC) methods for ionization potentials (IP-EOM-CC) have been derived and computer implemented by virtue of a symbolic algebra system largely automating these processes. Models with connected cluster excitation operators truncated after double, triple, or quadruple level and with linear ionization operators truncated after two-hole-one-particle (2h1p), three-hole-two-particle (3h2p), or four-hole-three-particle (4h3p) level (abbreviated as IP-EOM-CCSD, CCSDT, and CCSDTQ, respectively) have been realized into parallel algorithms taking advantage of spin, spatial, and permutation symmetries with optimal size dependence of the computational costs. They are based on spin-orbital formalisms and can describe both alpha and beta ionizations from open-shell (doublet, triplet, etc.) reference states into ionized states with various spin magnetic quantum numbers. The application of these methods to Koopmans and satellite ionizations of N2 and CO (with the ambiguity due to finite basis sets eliminated by extrapolation) has shown that IP-EOM-CCSD frequently accounts for orbital relaxation inadequately and displays errors exceeding a couple of eV. However, these errors can be systematically reduced to tenths or even hundredths of an eV by IP-EOM-CCSDT or CCSDTQ. Comparison of spectroscopic parameters of the FH+ and NH+ radicals between IP-EOM-CC and experiments has also underscored the importance of higher-order IP-EOM-CC treatments. For instance, the harmonic frequencies of the A 2Sigma- state of NH+ are predicted to be 1285, 1723, and 1705 cm(-1) by IP-EOM-CCSD, CCSDT, and CCSDTQ, respectively, as compared to the observed value of 1707 cm(-1). The small adiabatic energy separation (observed 0.04 eV) between the X 2Pi and a 4Sigma- states of NH+ also requires IP-EOM-CCSDTQ for a quantitative prediction (0.06 eV) when the a 4Sigma- state has the low-spin magnetic quantum number (s(z) = 1/2). When the state with s(z) = 3/2 is sought, the energy separations converge much more rapidly with the IP-EOM-CCSD value (0.03 eV) already being close to the observed (0.04 eV).
Collapse
Affiliation(s)
- Muneaki Kamiya
- Quantum Theory Project, Department of Chemistry, University of Florida, Gainesville, Florida 32611-8435, USA
| | | |
Collapse
|
11
|
Sun * W, Ren W, Hou S, Feng H. Studies on full vibrational spectra and dissociation energies of some diatomic molecular electronic states using algebraic approaches. Mol Phys 2005. [DOI: 10.1080/01449290500102185] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
12
|
Leach S, Jochims HW, Baumgärtel H. VUV Photodissociation of ammonia: a dispersed fluorescence excitation spectral study. Phys Chem Chem Phys 2005; 7:900-11. [DOI: 10.1039/b409046m] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
13
|
Haworth NL, Mackie JC, Bacskay GB. An Ab Initio Quantum Chemical and Kinetic Study of the NNH + O Reaction Potential Energy Surface: How Important Is This Route to NO in Combustion? J Phys Chem A 2003. [DOI: 10.1021/jp034421p] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Naomi L. Haworth
- School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
| | - John C. Mackie
- School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
| | - George B. Bacskay
- School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
| |
Collapse
|
14
|
Henry DJ, Parkinson CJ, Radom L. An Assessment of the Performance of High-Level Theoretical Procedures in the Computation of the Heats of Formation of Small Open-Shell Molecules. J Phys Chem A 2002. [DOI: 10.1021/jp0260752] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- David J. Henry
- Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia
| | | | - Leo Radom
- Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia
| |
Collapse
|
15
|
Affiliation(s)
- K M Ervin
- Department of Chemistry and Chemical Physics Program, University of Nevada, Reno, Nevada 89557, USA.
| |
Collapse
|