Using the numerical solution of the time-dependent SchrSdinger equation of a one-dimensional model atom in a two-colour laser field, we have investigated the effects of the potential models on coherent control of atom...Using the numerical solution of the time-dependent SchrSdinger equation of a one-dimensional model atom in a two-colour laser field, we have investigated the effects of the potential models on coherent control of atomic multiphoton ionization. It is found that the photoelectron spectra are obviously different for the long-range (Coulomb-like) and short-range (with no excited bound states) potential model atoms, which are produced by two-colour coherent control of atomic multiphoton ionization in a few laser cycles. Our results indicate that two-colour coherent control of atomic multiphoton ionization can be observed in simulations, depending on the choice of the model potentials.展开更多
Adiabatic and vertical ionization potentials (IPs) mad valence electron affmities (EAs) of alaninamide in gas phase have been detennined using density functional theory (BLYP, B3LYP, B3P86) methods with 6-311+...Adiabatic and vertical ionization potentials (IPs) mad valence electron affmities (EAs) of alaninamide in gas phase have been detennined using density functional theory (BLYP, B3LYP, B3P86) methods with 6-311++G(d, p) basis set, respectively. IPs and EAs of alaninamide in solutions have been calculated at the B3LYP/6-311++G(d, p) level. Five possible conformers of alaninamide and their charged states have been optimized employing density functional theory B3LYP method with 6-311++(d, p) basis set, respectively.展开更多
The properties of Pbn(n=2―30) clusters including binding energies,second differences in energy,and HOMO-LUMO gaps,especially fragmentation energies and ionization potentials,have been studied by ab initio calculati...The properties of Pbn(n=2―30) clusters including binding energies,second differences in energy,and HOMO-LUMO gaps,especially fragmentation energies and ionization potentials,have been studied by ab initio calculation.The main fragmentation products of Pbn+ are shown to be Pb+Pbn-1+ for n≤14 and two small cluster fragments for larger ones with n14.The Pb13+ appears frequently as the products in the fragmentations of large clusters.Also,the calculated ionization potentials of the clusters are consistent with the experiment data.展开更多
Abstract In this work, ionization potentials and quantum effects of ls^2 np^2 P Rydberg states of lithium are calculated based on the calibrated quantum defect function. Energy levels and quantum defects for ls^2np^2P...Abstract In this work, ionization potentials and quantum effects of ls^2 np^2 P Rydberg states of lithium are calculated based on the calibrated quantum defect function. Energy levels and quantum defects for ls^2np^2P bound states and their adjacent continuum states are calculated with the R-matrix theory, and then the quantum defect function of the ls^2np (n ≥ 7) channel is obtained, which varies smoothly with the energy based on the quantum defect theory. The accurate quantum defect of the ls^2 7p^2P state derived from the experimental data is used to calibrate the original quantum defect function. The new function is used to calculate ionization potentials and quantum effects of ls^2np ^2P (n ≥ 7) Rydberg states. Present calculations are in agreement with recent experimental data in whole.展开更多
The multi-configuration Dirac-Fock method is used in this work to calculate ground-state ionization potentials of Boron and Carbon isoelectronic sequences from Z = 6 to Z=42. And the contribution of relativistic corre...The multi-configuration Dirac-Fock method is used in this work to calculate ground-state ionization potentials of Boron and Carbon isoelectronic sequences from Z = 6 to Z=42. And the contribution of relativistic corrections, nuclear volume effect, Breit and QED effects to tile results is discussed in the calculation. The results are compared with the scanty existing theoretical and experimental data in the literature and good agreements are achieved. Then analytical expressions of lonization potential along Boron and Carbon isoelectronic sequences are obtained.展开更多
Al2-Al40 clusters were studied by means of the all-electron DFT method. The properties of the aluminum clusters including binding energy, the second difference in energy, HOMO-LUMO gap, especially fragmentation energi...Al2-Al40 clusters were studied by means of the all-electron DFT method. The properties of the aluminum clusters including binding energy, the second difference in energy, HOMO-LUMO gap, especially fragmentation energies and ionization potentials, were analyzed. The main products from the dissociations of aluminum cluster ions are shown to be Al + Al^+n-1 for the larger clusters, and Al^+ +Aln-1 for the smaller ones. And, the calculated ionization potentials are consistent with the experiment data.展开更多
We systematically investigate the influence of atomic potentials on the above-threshold ionization (ATI) spectra in one-dimensional (1D) cases and compare them with the three-dimensional (3D) case by numerically...We systematically investigate the influence of atomic potentials on the above-threshold ionization (ATI) spectra in one-dimensional (1D) cases and compare them with the three-dimensional (3D) case by numerically solving the time-dependent Schrrdinger equation. It is found that the direct ionization plateau and the rescattering plateau of the ATI spectrum in the 3D case can be well reproduced by the 1D ATI spectra calculated from the supersolid-core potential and the soft-core potential, respectively. By analyzing the factors that affect the yield of the ATI spectrum, we propose a modified-potential with which we can reproduce the overall 3D ATI spectrum. In addition, the influence of the incident laser intensities and frequencies on the ATI spectra calculated from the proposed modified potential is studied.展开更多
By means of the energy level formula E(p)=α+2βcos(pπ/(n+t+1)). the pseudo π ionization potentials of H-(CH_2)_n-X (X=H, F, Cl, Br, I, OH, and SH) are identified by optimizing linear regression analysis, from which...By means of the energy level formula E(p)=α+2βcos(pπ/(n+t+1)). the pseudo π ionization potentials of H-(CH_2)_n-X (X=H, F, Cl, Br, I, OH, and SH) are identified by optimizing linear regression analysis, from which α=13.54±0.50eV and β=1.75±0.13eV are obtained.展开更多
Ionization potentials and electron affinities of Cux (n = 2-7) atomic clusters with the optimal geom etries have been calculated by use of SC F-Xa-SW method and Slater's transition state theory. Theo retical calc...Ionization potentials and electron affinities of Cux (n = 2-7) atomic clusters with the optimal geom etries have been calculated by use of SC F-Xa-SW method and Slater's transition state theory. Theo retical calcuIations show that the ionization potentiaIs and electron affinities of Cu. (n = 2-7) atom ic clusters have a sharp even / odd alternation with increasing their sizes, which are related to the electronic structure of Cun atomic clusters. The theoretical results are consistent with the related ex perimental ones.展开更多
Recently,the quantitative rescattering model(QRS)for nonsequential double ionization(NSDI)is modified by taking into account the potential change(PC)due to the presence of electric field at the time of recollision.Usi...Recently,the quantitative rescattering model(QRS)for nonsequential double ionization(NSDI)is modified by taking into account the potential change(PC)due to the presence of electric field at the time of recollision.Using the improved QRS model,we simulate the longitudinal momentum distributions of doubly charged ions He2+by projecting the correlated two-electron momentum distributions for NSDI of He onto the main diagonal.The obtained results are compared directly with the experimental data at different intensities.It is found that when the PC is considered,the width of momentum distributions reduces and the agreement between theory and experiment is improved.展开更多
The relations of oxygen content, critical temperature TC and mean ionization potential < U0> of superconducting oxides are reported. We found that in oxides oxygen is the major element which governs their < U...The relations of oxygen content, critical temperature TC and mean ionization potential < U0> of superconducting oxides are reported. We found that in oxides oxygen is the major element which governs their < U0> te values and thus oxygen content plays an jmportant role in their superconducting properties. As for Y(123)- and T1-systems oxygenation may improve their TC values, but for Biand Hg-systems oxygenation process is not so important. In Y(123), as the oxygen content increase results in the increase of TC upon < U0>to, while the substitution of Ba2+ by Sr2+ causes the decrease of TC upon < U0 >. These results may provide some clues about the superconductivity of oxides and support further that < Uo > is really a good criterion for oxide superconductivity. Two kinds of possible superconducting oxides are predicted in this paper according to the mean ionization potential criterion.展开更多
The authors found the effect of magnetic field on the ionization of atoms and ions and shown that the magnetic field affected the rate of ionization and electron emission at angle of 60°, 120°, 240° and...The authors found the effect of magnetic field on the ionization of atoms and ions and shown that the magnetic field affected the rate of ionization and electron emission at angle of 60°, 120°, 240° and 300°. It is shown that the calculation must take into account the ionization potential of the magnetic field.展开更多
The electronic structure of Ag_n and Au_n(n=2,3,4) calculated by DV—X_α method, are different each other, and the ionization potentials of Ag_n and Au_n as a function of cluster size n exhibit an interesting 'sa...The electronic structure of Ag_n and Au_n(n=2,3,4) calculated by DV—X_α method, are different each other, and the ionization potentials of Ag_n and Au_n as a function of cluster size n exhibit an interesting 'saw—tooth' behavior. The interactions between atom Ag—Ag and Au —Au in Ag_2, Au_2 for different bond length are analyzed. The DOS of the orbitals shows those interactions directly.展开更多
We theoretically investigate the low energy part of the photoelectron spectra in the tunneling ionization regime by numerically solving the time-dependent Schrdinger equation for different atomic potentials at various...We theoretically investigate the low energy part of the photoelectron spectra in the tunneling ionization regime by numerically solving the time-dependent Schrdinger equation for different atomic potentials at various wavelengths.We find that the shift of the first above-threshold ionization(ATI) peak is closely related to the interferences between electron wave packets,which are controlled by the laser field and largely independent of the potential.By gradually changing the short-range potential to the long-range Coulomb potential,we show that the long-range potential's effect is mainly to focus the electrons along the laser's polarization and to generate the spider structure by enhancing the rescattering process with the parent ion.In addition,we find that the intermediate transitions and the Rydberg states have important influences on the number and the shape of the lobes near the threshold.展开更多
The Ionization Potential (IP) is qualitatively de ned as the amount of energy to remove the most loosely bound electron of an isolated gaseous atom to form a cation, or the released energy of moving a single electron ...The Ionization Potential (IP) is qualitatively de ned as the amount of energy to remove the most loosely bound electron of an isolated gaseous atom to form a cation, or the released energy of moving a single electron from in nity to the surface of a cation. So the IP value is related to the electronic structure and is one of the fundamental parameters of the atom. We introduced a new experimental method to measure the Rydberg state energy levels of 87Rb atom and got its rst ionization potential to be 33 690.946(7) cm??1.展开更多
The potential energy surfaces for butanone isomerization have been investigated by density function theory calculation. Six main reaction pathways are confirmed using the intrinsic reaction coordinate method, and the ...The potential energy surfaces for butanone isomerization have been investigated by density function theory calculation. Six main reaction pathways are confirmed using the intrinsic reaction coordinate method, and the corresponding isomerization products are 1-buten-2-ol, 2-buten-2-ol, butanal or 1-buten-l-ol, methyl 1-propenyl ether, methyl allyl ether, and ethyl vinyl ether, respectively. Among them, there are three pathways through butylene oxide, indicating butylene oxide is an important intermediate product during butanone isomer ization. The calculated vertical ionization energies of the reactant and its products are in a good agreement with the experimental values available. From the consideration for the relative energies Of transition states and the number of high-energy barriers we infer that the reaction pathway butanone-*l-buten-2-ol---2-buten-2-oi is the most competitive. The obtained results are informative for future studies on isomerization of ketone molecules.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 10674112) and the Young Teachers Foundation of Northwest Normal University (Grant No NWNU-QN-04-25).
文摘Using the numerical solution of the time-dependent SchrSdinger equation of a one-dimensional model atom in a two-colour laser field, we have investigated the effects of the potential models on coherent control of atomic multiphoton ionization. It is found that the photoelectron spectra are obviously different for the long-range (Coulomb-like) and short-range (with no excited bound states) potential model atoms, which are produced by two-colour coherent control of atomic multiphoton ionization in a few laser cycles. Our results indicate that two-colour coherent control of atomic multiphoton ionization can be observed in simulations, depending on the choice of the model potentials.
基金the Natural Science Foundation of Shandong Province (Z2004F01)the State Key Laboratory Foundation of Crystal Materialthe National Natural Science Foundation of China (29673025)
文摘Adiabatic and vertical ionization potentials (IPs) mad valence electron affmities (EAs) of alaninamide in gas phase have been detennined using density functional theory (BLYP, B3LYP, B3P86) methods with 6-311++G(d, p) basis set, respectively. IPs and EAs of alaninamide in solutions have been calculated at the B3LYP/6-311++G(d, p) level. Five possible conformers of alaninamide and their charged states have been optimized employing density functional theory B3LYP method with 6-311++(d, p) basis set, respectively.
基金Supported by the National Natural Science Foundation of China(Nos.20773047 and 21043001)
文摘The properties of Pbn(n=2―30) clusters including binding energies,second differences in energy,and HOMO-LUMO gaps,especially fragmentation energies and ionization potentials,have been studied by ab initio calculation.The main fragmentation products of Pbn+ are shown to be Pb+Pbn-1+ for n≤14 and two small cluster fragments for larger ones with n14.The Pb13+ appears frequently as the products in the fragmentations of large clusters.Also,the calculated ionization potentials of the clusters are consistent with the experiment data.
基金National Natural Science Foundation of China under Grant No.10404017the Basic Research Foundation of Beijing Institute of Technology
文摘Abstract In this work, ionization potentials and quantum effects of ls^2 np^2 P Rydberg states of lithium are calculated based on the calibrated quantum defect function. Energy levels and quantum defects for ls^2np^2P bound states and their adjacent continuum states are calculated with the R-matrix theory, and then the quantum defect function of the ls^2np (n ≥ 7) channel is obtained, which varies smoothly with the energy based on the quantum defect theory. The accurate quantum defect of the ls^2 7p^2P state derived from the experimental data is used to calibrate the original quantum defect function. The new function is used to calculate ionization potentials and quantum effects of ls^2np ^2P (n ≥ 7) Rydberg states. Present calculations are in agreement with recent experimental data in whole.
基金Supported by the Science Fund for Young Scholars of Southwest University under Grant No.SWU208035 Fundamental Research Funds of Central University under Grant No.XDJK2009C020
文摘The multi-configuration Dirac-Fock method is used in this work to calculate ground-state ionization potentials of Boron and Carbon isoelectronic sequences from Z = 6 to Z=42. And the contribution of relativistic corrections, nuclear volume effect, Breit and QED effects to tile results is discussed in the calculation. The results are compared with the scanty existing theoretical and experimental data in the literature and good agreements are achieved. Then analytical expressions of lonization potential along Boron and Carbon isoelectronic sequences are obtained.
基金Supported by the National Natural Science Foundation of China(Nos.20773047 and 20473030)
文摘Al2-Al40 clusters were studied by means of the all-electron DFT method. The properties of the aluminum clusters including binding energy, the second difference in energy, HOMO-LUMO gap, especially fragmentation energies and ionization potentials, were analyzed. The main products from the dissociations of aluminum cluster ions are shown to be Al + Al^+n-1 for the larger clusters, and Al^+ +Aln-1 for the smaller ones. And, the calculated ionization potentials are consistent with the experiment data.
基金Project supported by the National Basic Research Program of China(Grant No.2013CB922200)the National Natural Science Foundation of China(Grant Nos.11274141,11034003,11304116,11274001,and 11247024)the Jilin Provincial Research Foundation for Basic Research,China(Grant No.20140101168JC)
文摘We systematically investigate the influence of atomic potentials on the above-threshold ionization (ATI) spectra in one-dimensional (1D) cases and compare them with the three-dimensional (3D) case by numerically solving the time-dependent Schrrdinger equation. It is found that the direct ionization plateau and the rescattering plateau of the ATI spectrum in the 3D case can be well reproduced by the 1D ATI spectra calculated from the supersolid-core potential and the soft-core potential, respectively. By analyzing the factors that affect the yield of the ATI spectrum, we propose a modified-potential with which we can reproduce the overall 3D ATI spectrum. In addition, the influence of the incident laser intensities and frequencies on the ATI spectra calculated from the proposed modified potential is studied.
文摘By means of the energy level formula E(p)=α+2βcos(pπ/(n+t+1)). the pseudo π ionization potentials of H-(CH_2)_n-X (X=H, F, Cl, Br, I, OH, and SH) are identified by optimizing linear regression analysis, from which α=13.54±0.50eV and β=1.75±0.13eV are obtained.
文摘Ionization potentials and electron affinities of Cux (n = 2-7) atomic clusters with the optimal geom etries have been calculated by use of SC F-Xa-SW method and Slater's transition state theory. Theo retical calcuIations show that the ionization potentiaIs and electron affinities of Cu. (n = 2-7) atom ic clusters have a sharp even / odd alternation with increasing their sizes, which are related to the electronic structure of Cun atomic clusters. The theoretical results are consistent with the related ex perimental ones.
基金Project supported by the National Natural Science Foundation of China(Grant No.11274219)the Science and Technology Planning Project of Guangdong Province of China(Grant No.180917124960522)the Program for Promotion of Science at Universities in Guangdong Province of China(Grant No.2018KTSCX062)。
文摘Recently,the quantitative rescattering model(QRS)for nonsequential double ionization(NSDI)is modified by taking into account the potential change(PC)due to the presence of electric field at the time of recollision.Using the improved QRS model,we simulate the longitudinal momentum distributions of doubly charged ions He2+by projecting the correlated two-electron momentum distributions for NSDI of He onto the main diagonal.The obtained results are compared directly with the experimental data at different intensities.It is found that when the PC is considered,the width of momentum distributions reduces and the agreement between theory and experiment is improved.
文摘The relations of oxygen content, critical temperature TC and mean ionization potential < U0> of superconducting oxides are reported. We found that in oxides oxygen is the major element which governs their < U0> te values and thus oxygen content plays an jmportant role in their superconducting properties. As for Y(123)- and T1-systems oxygenation may improve their TC values, but for Biand Hg-systems oxygenation process is not so important. In Y(123), as the oxygen content increase results in the increase of TC upon < U0>to, while the substitution of Ba2+ by Sr2+ causes the decrease of TC upon < U0 >. These results may provide some clues about the superconductivity of oxides and support further that < Uo > is really a good criterion for oxide superconductivity. Two kinds of possible superconducting oxides are predicted in this paper according to the mean ionization potential criterion.
文摘The authors found the effect of magnetic field on the ionization of atoms and ions and shown that the magnetic field affected the rate of ionization and electron emission at angle of 60°, 120°, 240° and 300°. It is shown that the calculation must take into account the ionization potential of the magnetic field.
基金The project supported by National Nature Science Foundation of China and National Advanced Materials Commlttee of China
文摘The electronic structure of Ag_n and Au_n(n=2,3,4) calculated by DV—X_α method, are different each other, and the ionization potentials of Ag_n and Au_n as a function of cluster size n exhibit an interesting 'saw—tooth' behavior. The interactions between atom Ag—Ag and Au —Au in Ag_2, Au_2 for different bond length are analyzed. The DOS of the orbitals shows those interactions directly.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11322437 and 11574010)the National Basic Research ProgramChina(Grant No.2013CB922402)
文摘We theoretically investigate the low energy part of the photoelectron spectra in the tunneling ionization regime by numerically solving the time-dependent Schrdinger equation for different atomic potentials at various wavelengths.We find that the shift of the first above-threshold ionization(ATI) peak is closely related to the interferences between electron wave packets,which are controlled by the laser field and largely independent of the potential.By gradually changing the short-range potential to the long-range Coulomb potential,we show that the long-range potential's effect is mainly to focus the electrons along the laser's polarization and to generate the spider structure by enhancing the rescattering process with the parent ion.In addition,we find that the intermediate transitions and the Rydberg states have important influences on the number and the shape of the lobes near the threshold.
基金National Natural Science Foundation of China(11274316, 21203216, 11404346), "One Hundred Talents Program" of Chinese Academy of Sciences
文摘The Ionization Potential (IP) is qualitatively de ned as the amount of energy to remove the most loosely bound electron of an isolated gaseous atom to form a cation, or the released energy of moving a single electron from in nity to the surface of a cation. So the IP value is related to the electronic structure and is one of the fundamental parameters of the atom. We introduced a new experimental method to measure the Rydberg state energy levels of 87Rb atom and got its rst ionization potential to be 33 690.946(7) cm??1.
文摘The potential energy surfaces for butanone isomerization have been investigated by density function theory calculation. Six main reaction pathways are confirmed using the intrinsic reaction coordinate method, and the corresponding isomerization products are 1-buten-2-ol, 2-buten-2-ol, butanal or 1-buten-l-ol, methyl 1-propenyl ether, methyl allyl ether, and ethyl vinyl ether, respectively. Among them, there are three pathways through butylene oxide, indicating butylene oxide is an important intermediate product during butanone isomer ization. The calculated vertical ionization energies of the reactant and its products are in a good agreement with the experimental values available. From the consideration for the relative energies Of transition states and the number of high-energy barriers we infer that the reaction pathway butanone-*l-buten-2-ol---2-buten-2-oi is the most competitive. The obtained results are informative for future studies on isomerization of ketone molecules.