The SiS molecule,which plays a significant role in space,has attracted a great deal of attention for many years.Due to complex interactions among its low-lying electronic states,precise information regarding the molec...The SiS molecule,which plays a significant role in space,has attracted a great deal of attention for many years.Due to complex interactions among its low-lying electronic states,precise information regarding the molecular structure of SiS is limited.To obtain accurate information about the structure of its excited states,the high-precision multireference configuration interaction(MRCI)method has been utilized.This method is used to calculate the potential energy curves(PECs)of the 18Λ–S states corresponding to the lowest dissociation limit of SiS.The core–valence correlation effect,Davidson’s correction and the scalar relativistic effect are also included to guarantee the precision of the MRCI calculation.Based on the calculated PECs,the spectroscopic constants of quasi-bound and bound electronic states are calculated and they are in accordance with previous experimental results.The transition dipole moments(TDMs)and dipole moments(DMs)are determined by the MRCI method.In addition,the abrupt variations of the DMs for the 1^(5)Σ^(+)and 2^(5)Σ^(+)states at the avoided crossing point are attributed to the variation of the electronic configuration.The opacity of SiS at a pressure of 100 atms is presented across a series of temperatures.With increasing temperature,the expanding population of excited states blurs the band boundaries.展开更多
We theoretically investigate high-order harmonic generation(HHG) of helium(He), lithium cation(Li+), and beryllium dication(Be2+) using the time-dependent Hartree–Fock method to solve the three-dimensional time-depen...We theoretically investigate high-order harmonic generation(HHG) of helium(He), lithium cation(Li+), and beryllium dication(Be2+) using the time-dependent Hartree–Fock method to solve the three-dimensional time-dependent Schr ¨odinger equation. It is found that the intensity of the HHG increases significantly from a certain harmonic order below the ionization threshold, and the initial position of the enhancement does not depend on the intensity or the wavelength of the driving laser field. Further analysis shows that excited states play an important role on this enhancement,consistent with the excited-state tunneling mechanism [Phys. Rev. Lett. 116 123901(2016)]. Our results unambiguously show that excited-state tunneling is essential for understanding the enhancement of HHG. Accordingly, a four-step model is herein proposed to illustrate the multiphoton excitation effect in helium-like ions, which enriches the physics of HHG enhancement.展开更多
In the present work,we extend the Coulomb and Proximity Potential Model(CPPM)to study two-proton(2p)radioactivity from excited states while the proximity potential is chosen as AW95 proposed by Aage Withner in 1995.De...In the present work,we extend the Coulomb and Proximity Potential Model(CPPM)to study two-proton(2p)radioactivity from excited states while the proximity potential is chosen as AW95 proposed by Aage Withner in 1995.Demonstration reveals that the theoretical results acquired by CPPM exhibit a high level of consistency with prior theoretical models such as the unified fission model(UFM),generalized liquid-drop model(GLDM)and effective liquid-drop model(ELDM).Furthermore,within the CPPM,we predicted the half-lives of potential 2p radioactive nuclei for which experimental data are currently unavailable.The predicted results were then assessed,compared with UFM,ELDM and GLDM models,and examined in detail.展开更多
In this paper, we have declined the formalism of the method of the Modified Atomic Orbital Theory (MAOT) applied to the calculations of energies of doubly excited states 2<em>snp</em>, 3<em>snp</e...In this paper, we have declined the formalism of the method of the Modified Atomic Orbital Theory (MAOT) applied to the calculations of energies of doubly excited states 2<em>snp</em>, 3<em>snp</em>, and 4<em>snp</em> Helium-like systems. Then we also applied the variational procedure of the Modified Atomic Orbital Theory to the computations of total energies, excitation energies of doubly-excited states 2<em>snp</em>, 3<em>snp</em>, 4<em>snp</em> types of Helium-like systems. The results obtained in this work are in good agreement with the experimental and theoretical values available.展开更多
The geometries and vibrational frequencies of the ground and low-lying excited states for B_3, B_3^- and B_3^+ are determined with the energy gradient method using the polarized double-zeta(6-31G*) basis set. The stab...The geometries and vibrational frequencies of the ground and low-lying excited states for B_3, B_3^- and B_3^+ are determined with the energy gradient method using the polarized double-zeta(6-31G*) basis set. The stabilities for the states of B_3,B_3^- and B_3^+ have been investigated based on the vibrational analysis. The correlation energy obtained for each state is considered with the configuration interaction (CISD+Q) technique. B_3 and B_3^+ have stable equilateral triangle geometry, while B_3^- has stable equilateral triangle, isosceles triangle and linear geometries. The Jahn-Teller distortion for a ~3E' state of B_3^- in D_(3h) symmetry is also discussed.展开更多
By taking full account of the non-orthogonality of the orbitals between the low-lying doubly excited states ^1po and the singly excited states ^1S^e and ^1D^e of He, the corresponding radiative decay rates have been i...By taking full account of the non-orthogonality of the orbitals between the low-lying doubly excited states ^1po and the singly excited states ^1S^e and ^1D^e of He, the corresponding radiative decay rates have been investigated theoretically via analytic generalized Laguerre-type atomic orbitals at a nearly numerical multi-conflguration self-consistent field accuracy in a general non-orthogonal configuration interaction scheme. From these rates, we calculate the VUV photon emission and metastable atom spectra, and both are found to be in good qualitative agreement with recent excellent measurements. We obtain, successfully, the enhancement of the VUV photon spectrum, experimentally observed at the energy of (2s4p-4s2p)/(2p,3d) ^1po as compared with other nearby lying states. The mechanism proposed by Odling-Smee et al is verified, implying that taking appropriate account of the overlap existing between orbitals of the low-lying doubly excited and singly excited states (especially important for the compact orbitals) can reveal basic physical dominant mechanism and is crucial in understanding these spectra.展开更多
We measure the intensity of fluorescence spectral lines of Cs atoms in an electrodeless discharge lamp from visible light to the near-infrared region of 400-100Ohm. To build an excited state Faraday anomalous dispersi...We measure the intensity of fluorescence spectral lines of Cs atoms in an electrodeless discharge lamp from visible light to the near-infrared region of 400-100Ohm. To build an excited state Faraday anomalous dispersion optical filter, the population ratios between the excited states are calculated by rate equations and the spontaneous transition probabilities. The electrodeless discharge lamp with populations in the excited states can be used to realize the frequency stabilization reference for lasers at multiwavelength and the excited state Faraday anomalous dispersion optical filter for submarine communication applications in blue-green wavelengths to simplify the system.展开更多
In this work, the total energies of doubly excited states (<em>ns</em><sup>2</sup>) <sup>1</sup>S<sup>e</sup>, (<em>np</em><sup>2</sup>) <sup&...In this work, the total energies of doubly excited states (<em>ns</em><sup>2</sup>) <sup>1</sup>S<sup>e</sup>, (<em>np</em><sup>2</sup>) <sup>1</sup>D<sup>e</sup>, (<em>nd</em><sup>2</sup>) <sup>1</sup>G<sup>e</sup>, (<em>nf</em><sup>2</sup>) <sup>1</sup>I<sup>e</sup>, (<em>ng</em><sup>2</sup>) <sup>1</sup>K<sup>e</sup>, and (<em>nh</em><sup>2</sup>) <sup>1</sup>M<sup>e</sup> of the helium isoelectronic sequence with Z ≤ 10 are calculated in the framework of the variational method of the Screening Constant by Unit Nuclear Charge (SCUNC). These calculations are performed using a new wavefunction correlated to Hylleraas-type. The possibility of using the SCUNC method in the investigation of high-lying Doubly Excited States(DES) in two-electron systems is demonstrated in the present work in the case of the (<em>nl</em><sup>2</sup>) <sup>1</sup><em>L</em><sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><em>π</em></span></span></span></sup> doubly excited states, where accurate total energies are tabulated up to <em>n</em> = 20. All the results obtained in this paper are in agreement with the values of the available literature and may be useful for future experimental and theoretical studies on the doubly excited (<em>nl</em><sup>2</sup>) <sup>1</sup><em>L</em><sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><em>π</em></span></span></sup> states of two-electron systems.展开更多
Based on the obtained energy values of 1s^2np (n≤ 9) states for lithium-like systems from Z=11 to 20 (by the authors of this paper: Hu M H and Wang Z W 2004 Chin. Phys. 13 662), this paper determines the quantum...Based on the obtained energy values of 1s^2np (n≤ 9) states for lithium-like systems from Z=11 to 20 (by the authors of this paper: Hu M H and Wang Z W 2004 Chin. Phys. 13 662), this paper determines the quantum defects, as slowly varying function of energy, of this Rydberg series. Using them as input, it can predict the energies of any highly excited states below the ionization threshold for this series a^cording to the quantum defect theory. The regularities of variation for quantum defects of the series along this isoelectronic sequence are physically analysed and discussed. The screening parameters, which are equal to the effective screening charge of the core-electrons, are also obtained.展开更多
We theoretically investigate the contribution of the excited state to the ellipticity of the harmonics from H+ at different orientation angles irradiated by a linearly polarized laser pulse. It is found that the firs...We theoretically investigate the contribution of the excited state to the ellipticity of the harmonics from H+ at different orientation angles irradiated by a linearly polarized laser pulse. It is found that the first excited state has a significant influence to the ellipticity of the harmonics, and the contribution of higher excited states to the ellipticity can be neglected. Moreover, the conclusion is not dependent on the laser intensity.展开更多
Excited-state hydrogen-bonding dynamics of N-methylformamide (NMF) in water has been investigated by time-dependent density functional theory (TDDFT) method. The ground-state geometry optimizations were calculated...Excited-state hydrogen-bonding dynamics of N-methylformamide (NMF) in water has been investigated by time-dependent density functional theory (TDDFT) method. The ground-state geometry optimizations were calculated by density functional theory (DFT) method, while the electronic transition energies and corresponding oscillation strengths of the low-lying electronically excited states of isolated NMF, water monomers and the hydrogen-bonded NMF-H 2 O were calculated by TDDFT method. According to Zhao's rule on the excited-state hydrogen bonding dynamics, our results demonstrate that the intermolecular hydrogen bond C=O···O-H is strengthened and weakened in different electronically excited states. The hydrogen bond strengthening and weakening in the electronically excited state plays an important role in the photophysics of NMF in solutions.展开更多
Scalar properties and vector correlations of the reactions of O+H2 →OH+H, O+HD→OH+D, O+DH→OD+H, and O+D2 -+OD+D at collision energies of 25 and 34.6 kcal/mole have been studied via the quasi-classical-traj...Scalar properties and vector correlations of the reactions of O+H2 →OH+H, O+HD→OH+D, O+DH→OD+H, and O+D2 -+OD+D at collision energies of 25 and 34.6 kcal/mole have been studied via the quasi-classical-trajectory (QCT) method based on a BMS1 potential energy surface (PES). The generalized polarization-dependent differential cross section and the distributions of the dihedral angle at the collision energy of 34.6 kacl/mole are presented. The calculated results indicate that both the reagent rotational angular momentum and the mass factor have a significant influence on the scalar properties and vector correlations of the title reactions.展开更多
The convergent iterative procedure for solving the groundstate Schrodinger equation is extended to derive the excitation energy and the wavefunction of the low-lying excited states. The method is applied to the one-di...The convergent iterative procedure for solving the groundstate Schrodinger equation is extended to derive the excitation energy and the wavefunction of the low-lying excited states. The method is applied to the one-dimensional quartic potential problem. The results show that the iterative solution converges rapidly when the coupling g is not too small.展开更多
A variational-integral perturbation method(VIPM) is established by combining the variational perturbation with the integral perturbation.The first-order corrected wave functions are constructed,and the second-order ...A variational-integral perturbation method(VIPM) is established by combining the variational perturbation with the integral perturbation.The first-order corrected wave functions are constructed,and the second-order energy corrections for the ground state and several lower excited states are calculated by applying the VIPM to the hydrogen atom in a strong uniform magnetic field.Our calculations demonstrated that the energy calculated by the VIPM only shows a negative value,which indicates that the VIPM method is more accurate than the other methods.Our study indicated that the VIPM can not only increase the accuracy of the results but also keep the convergence of the wave functions.展开更多
While nickel(II)complexes have been widely used as catalysts for carbon-carbon coupling reactions,the exploration of their photophysical and photochemical properties is still in the infancy.Here,a series of square-pla...While nickel(II)complexes have been widely used as catalysts for carbon-carbon coupling reactions,the exploration of their photophysical and photochemical properties is still in the infancy.Here,a series of square-planar Ni(II)complexes[(diNHC)NiX2]bearing chelating benzimidazole-based bis(N-heterocyclic carbene)ligands and varying anionic coligands(1,X=Cl;2,X=Br;3,X=I)are synthesized and structurally characterized.In solid state,both 1 and 2 exhibit orange-red photoluminescence under ambient conditions.The photophysical and electrochemical measurements along with density functional theory(DFT)calculations reveal that the low-energy emissions can be attributed to singlet excited states with ligand-to-ligand charge-transfer(LLCT)character.This work suggests that strong-field N-heterocyclic carbene ligands play a crucial role to achieve the luminescence of Ni(II)complexes.展开更多
The purpose of this paper is to verify that the computational scheme from[Heid et al.,Gradient flow finite element discretizations with energy-based adaptivity for the Gross–Pitaevskii equation,J.Comput.Phys.436(2021...The purpose of this paper is to verify that the computational scheme from[Heid et al.,Gradient flow finite element discretizations with energy-based adaptivity for the Gross–Pitaevskii equation,J.Comput.Phys.436(2021)]for the numerical approximation of the ground state of the Gross–Pitaevskii equation can equally be applied for the effective approximation of excited states of Schr¨odinger’s equation.That procedure employs an adaptive interplay of a Sobolev gradient flow iteration and a novel local mesh refinement strategy,and yields a guaranteed energy decay in each step of the algorithm.The computational tests in the present work highlight that this strategy is indeed able to approximate excited states,with(almost)optimal convergence rate with respect to the number of degrees of freedom.展开更多
Organic room temperature phosphorescence(RTP) materials with persistent afterglow exhibit good biocompatibility, high signal to noise ratio and time resolved imaging characteristics in bio-applications. Moreover, they...Organic room temperature phosphorescence(RTP) materials with persistent afterglow exhibit good biocompatibility, high signal to noise ratio and time resolved imaging characteristics in bio-applications. Moreover, they can serve as hypoxia detection probes and photodynamic therapy agents for the sensitivity of triplet excitons toward oxygen in the surroundings. In this review, the recent progress of in vitro and in vivo afterglow bioimaging is presented by utilizing organic RTP materials. The strategies of molecular design and controlling methods of molecular packing were summarized, to prompt this new rising research field, with the emphasis on high intensity, ultralong lifetimes and red-shifted wavelengths of phosphorescence emission.展开更多
The investigation of electronic excited states in single-molecule junctions not only provides platforms to reveal the photophysical and photochemical processes at the molecular level,but also brings opportunities for ...The investigation of electronic excited states in single-molecule junctions not only provides platforms to reveal the photophysical and photochemical processes at the molecular level,but also brings opportunities for the development of single-molecule optoelectronic devices.Understanding the interaction mechanisms between molecules and nanocavities is essential to obtain ondemand properties in devices by artificial design,since molecules in junctions exhibit unique behaviors of excited states benefited from the structures of metallic nanocavities.Here,we review the excitation mechanisms involved in the interplay between molecules and plasmonic nanocavities,and reveal the influence of nanostructures on excited-state properties by demonstrating the differences in excited state decay processes.Furthermore,vibronic transitions of molecules between nanoelectrodes are also discussed,offering a new single-molecule characterization method.Finally,we provide the potential applications and challenges in single-molecule optoelectronic devices and the possible directions in exploring the underlying mechanisms of photophysical and photochemical processes.展开更多
A cluster-transfer experiment of 9Be(gBe,14 C --+ a+lOBe)e: at an incident energy of 45 MeV was carried out in order to investigate the molecular structure in high-lying resonant states in 14C. This reaction is o...A cluster-transfer experiment of 9Be(gBe,14 C --+ a+lOBe)e: at an incident energy of 45 MeV was carried out in order to investigate the molecular structure in high-lying resonant states in 14C. This reaction is of extremely large Q-value, making it an excellent case to select the reaction mechanism and the final states in outgoing nuclei. The high-lying resonances in 14C are reconstructed for three sets of well discriminated final states in 10Be. The results confirm the previous decay measurements with clearly improved decay-channel selections and also show a new state at 23.5(1) MeV. The resonant states at 22.4(3) and 24.0(3) MeV decay primarily into the typical molecular states at about 6 MeV in 10Be, indicating a well developed cluster structure in these high-lying states in l4C. Further measurements of more states of this kind are suggested.展开更多
Expectation values of single electron and interelectronic geometric quantities such as <γ>,<γ_(12)> ,<γ_(<)> , <γ_(>)>,<cosθ_(12)> and <θ_(12)> are calculated for doubly...Expectation values of single electron and interelectronic geometric quantities such as <γ>,<γ_(12)> ,<γ_(<)> , <γ_(>)>,<cosθ_(12)> and <θ_(12)> are calculated for doubly excited 2pnp ^(1)P^(e)(3 ≤ n ≤ 5), 2pnp ^(3)P^(e)(2 ≤ n ≤ 5)and 2pnd ^(1,3)D°(3 ≤ n ≤ 5) states of helium using Hylleraas-B-spline basis set. The energy levels converge to at least 10 significant digits in our calculations.The extrapolated values of geometric quantities except for <θ_(12)> reach 10 significant digits as well;<θ_(12)> reaches at least 7 significant digits using a multipole expansion approach. Our results provide a precise reference for future research.展开更多
基金Project supported by the Natural Science Foundation of Heilongjiang Province,China(Grant No.LH2022A026)the National Key Research and Development Program of China(Grant No.2022YFA1602500)+2 种基金the National Natural Science Foundation of China(Grant No.11934004)Fundamental Research Funds in Heilongjiang Province Universities,China(Grant No.145109309)Foundation of National Key Laboratory of Computational Physics(Grant No.6142A05QN22006)。
文摘The SiS molecule,which plays a significant role in space,has attracted a great deal of attention for many years.Due to complex interactions among its low-lying electronic states,precise information regarding the molecular structure of SiS is limited.To obtain accurate information about the structure of its excited states,the high-precision multireference configuration interaction(MRCI)method has been utilized.This method is used to calculate the potential energy curves(PECs)of the 18Λ–S states corresponding to the lowest dissociation limit of SiS.The core–valence correlation effect,Davidson’s correction and the scalar relativistic effect are also included to guarantee the precision of the MRCI calculation.Based on the calculated PECs,the spectroscopic constants of quasi-bound and bound electronic states are calculated and they are in accordance with previous experimental results.The transition dipole moments(TDMs)and dipole moments(DMs)are determined by the MRCI method.In addition,the abrupt variations of the DMs for the 1^(5)Σ^(+)and 2^(5)Σ^(+)states at the avoided crossing point are attributed to the variation of the electronic configuration.The opacity of SiS at a pressure of 100 atms is presented across a series of temperatures.With increasing temperature,the expanding population of excited states blurs the band boundaries.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12274294 and 12075036)。
文摘We theoretically investigate high-order harmonic generation(HHG) of helium(He), lithium cation(Li+), and beryllium dication(Be2+) using the time-dependent Hartree–Fock method to solve the three-dimensional time-dependent Schr ¨odinger equation. It is found that the intensity of the HHG increases significantly from a certain harmonic order below the ionization threshold, and the initial position of the enhancement does not depend on the intensity or the wavelength of the driving laser field. Further analysis shows that excited states play an important role on this enhancement,consistent with the excited-state tunneling mechanism [Phys. Rev. Lett. 116 123901(2016)]. Our results unambiguously show that excited-state tunneling is essential for understanding the enhancement of HHG. Accordingly, a four-step model is herein proposed to illustrate the multiphoton excitation effect in helium-like ions, which enriches the physics of HHG enhancement.
基金supported by the National Natural Science Foundation of China(Nos.12175100 and 11975132)the Construct Program of the Key Discipline in Hunan Province,the Research Foundation of Education Bureau of Hunan Province,China(No.18A237)+1 种基金the Natural Science Foundation of Hunan Province,China(No.2018JJ2321)the Innovation Group of Nuclear and Particle Physics in USC,the Opening Project of Cooperative Innovation Center for Nuclear Fuel Cycle Technology and Equipment,University of South China(No.2019KFZ10).
文摘In the present work,we extend the Coulomb and Proximity Potential Model(CPPM)to study two-proton(2p)radioactivity from excited states while the proximity potential is chosen as AW95 proposed by Aage Withner in 1995.Demonstration reveals that the theoretical results acquired by CPPM exhibit a high level of consistency with prior theoretical models such as the unified fission model(UFM),generalized liquid-drop model(GLDM)and effective liquid-drop model(ELDM).Furthermore,within the CPPM,we predicted the half-lives of potential 2p radioactive nuclei for which experimental data are currently unavailable.The predicted results were then assessed,compared with UFM,ELDM and GLDM models,and examined in detail.
文摘In this paper, we have declined the formalism of the method of the Modified Atomic Orbital Theory (MAOT) applied to the calculations of energies of doubly excited states 2<em>snp</em>, 3<em>snp</em>, and 4<em>snp</em> Helium-like systems. Then we also applied the variational procedure of the Modified Atomic Orbital Theory to the computations of total energies, excitation energies of doubly-excited states 2<em>snp</em>, 3<em>snp</em>, 4<em>snp</em> types of Helium-like systems. The results obtained in this work are in good agreement with the experimental and theoretical values available.
文摘The geometries and vibrational frequencies of the ground and low-lying excited states for B_3, B_3^- and B_3^+ are determined with the energy gradient method using the polarized double-zeta(6-31G*) basis set. The stabilities for the states of B_3,B_3^- and B_3^+ have been investigated based on the vibrational analysis. The correlation energy obtained for each state is considered with the configuration interaction (CISD+Q) technique. B_3 and B_3^+ have stable equilateral triangle geometry, while B_3^- has stable equilateral triangle, isosceles triangle and linear geometries. The Jahn-Teller distortion for a ~3E' state of B_3^- in D_(3h) symmetry is also discussed.
基金Project supported by the National Natural Science Foundation of China (Grant No 10347126), National High Technology Development Program of China (Grant No 2004AA306H10) and the Program "Excellence in the Research Institutes Supervised by the General Secretariat for Research and Technology / Ministry of Development", Greece.Acknowledgments Xiong Zhuang would like to express his appreciation for the partial support from the Greek State Scholarship Foundation (I.K.Y.) and the National Hellenic Research Foundation Scholarship for this work.
文摘By taking full account of the non-orthogonality of the orbitals between the low-lying doubly excited states ^1po and the singly excited states ^1S^e and ^1D^e of He, the corresponding radiative decay rates have been investigated theoretically via analytic generalized Laguerre-type atomic orbitals at a nearly numerical multi-conflguration self-consistent field accuracy in a general non-orthogonal configuration interaction scheme. From these rates, we calculate the VUV photon emission and metastable atom spectra, and both are found to be in good qualitative agreement with recent excellent measurements. We obtain, successfully, the enhancement of the VUV photon spectrum, experimentally observed at the energy of (2s4p-4s2p)/(2p,3d) ^1po as compared with other nearby lying states. The mechanism proposed by Odling-Smee et al is verified, implying that taking appropriate account of the overlap existing between orbitals of the low-lying doubly excited and singly excited states (especially important for the compact orbitals) can reveal basic physical dominant mechanism and is crucial in understanding these spectra.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11074011 and 91436210
文摘We measure the intensity of fluorescence spectral lines of Cs atoms in an electrodeless discharge lamp from visible light to the near-infrared region of 400-100Ohm. To build an excited state Faraday anomalous dispersion optical filter, the population ratios between the excited states are calculated by rate equations and the spontaneous transition probabilities. The electrodeless discharge lamp with populations in the excited states can be used to realize the frequency stabilization reference for lasers at multiwavelength and the excited state Faraday anomalous dispersion optical filter for submarine communication applications in blue-green wavelengths to simplify the system.
文摘In this work, the total energies of doubly excited states (<em>ns</em><sup>2</sup>) <sup>1</sup>S<sup>e</sup>, (<em>np</em><sup>2</sup>) <sup>1</sup>D<sup>e</sup>, (<em>nd</em><sup>2</sup>) <sup>1</sup>G<sup>e</sup>, (<em>nf</em><sup>2</sup>) <sup>1</sup>I<sup>e</sup>, (<em>ng</em><sup>2</sup>) <sup>1</sup>K<sup>e</sup>, and (<em>nh</em><sup>2</sup>) <sup>1</sup>M<sup>e</sup> of the helium isoelectronic sequence with Z ≤ 10 are calculated in the framework of the variational method of the Screening Constant by Unit Nuclear Charge (SCUNC). These calculations are performed using a new wavefunction correlated to Hylleraas-type. The possibility of using the SCUNC method in the investigation of high-lying Doubly Excited States(DES) in two-electron systems is demonstrated in the present work in the case of the (<em>nl</em><sup>2</sup>) <sup>1</sup><em>L</em><sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;"><em>π</em></span></span></span></sup> doubly excited states, where accurate total energies are tabulated up to <em>n</em> = 20. All the results obtained in this paper are in agreement with the values of the available literature and may be useful for future experimental and theoretical studies on the doubly excited (<em>nl</em><sup>2</sup>) <sup>1</sup><em>L</em><sup><span style="white-space:nowrap;"><span style="white-space:nowrap;"><em>π</em></span></span></sup> states of two-electron systems.
基金Project supported by the National Natural Science Foundation of China(Grant Nos 10474029 and 10774063)
文摘Based on the obtained energy values of 1s^2np (n≤ 9) states for lithium-like systems from Z=11 to 20 (by the authors of this paper: Hu M H and Wang Z W 2004 Chin. Phys. 13 662), this paper determines the quantum defects, as slowly varying function of energy, of this Rydberg series. Using them as input, it can predict the energies of any highly excited states below the ionization threshold for this series a^cording to the quantum defect theory. The regularities of variation for quantum defects of the series along this isoelectronic sequence are physically analysed and discussed. The screening parameters, which are equal to the effective screening charge of the core-electrons, are also obtained.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.91026021,11075068,10875054,11175076,and 10975065)the Fundamental Research Funds of the Central Universities of China(Grant No.lzujbky-2010-k08)
文摘We theoretically investigate the contribution of the excited state to the ellipticity of the harmonics from H+ at different orientation angles irradiated by a linearly polarized laser pulse. It is found that the first excited state has a significant influence to the ellipticity of the harmonics, and the contribution of higher excited states to the ellipticity can be neglected. Moreover, the conclusion is not dependent on the laser intensity.
基金Supported by the Fundamental Research Funds for the Central Universities (No.2012QN066,2011QN142)
文摘Excited-state hydrogen-bonding dynamics of N-methylformamide (NMF) in water has been investigated by time-dependent density functional theory (TDDFT) method. The ground-state geometry optimizations were calculated by density functional theory (DFT) method, while the electronic transition energies and corresponding oscillation strengths of the low-lying electronically excited states of isolated NMF, water monomers and the hydrogen-bonded NMF-H 2 O were calculated by TDDFT method. According to Zhao's rule on the excited-state hydrogen bonding dynamics, our results demonstrate that the intermolecular hydrogen bond C=O···O-H is strengthened and weakened in different electronically excited states. The hydrogen bond strengthening and weakening in the electronically excited state plays an important role in the photophysics of NMF in solutions.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61127012 and 60977063)the Scientific and Technical Innovation and Troop Construction Projects of Henan Province, China (Grant No.124200510013)
文摘Scalar properties and vector correlations of the reactions of O+H2 →OH+H, O+HD→OH+D, O+DH→OD+H, and O+D2 -+OD+D at collision energies of 25 and 34.6 kcal/mole have been studied via the quasi-classical-trajectory (QCT) method based on a BMS1 potential energy surface (PES). The generalized polarization-dependent differential cross section and the distributions of the dihedral angle at the collision energy of 34.6 kacl/mole are presented. The calculated results indicate that both the reagent rotational angular momentum and the mass factor have a significant influence on the scalar properties and vector correlations of the title reactions.
基金This research was supported in part by the U.S. Department of Energy (Grant No DE-FG02-92ER-40699) and the National Natural Science Foundation of China (Grant No 10547001).
文摘The convergent iterative procedure for solving the groundstate Schrodinger equation is extended to derive the excitation energy and the wavefunction of the low-lying excited states. The method is applied to the one-dimensional quartic potential problem. The results show that the iterative solution converges rapidly when the coupling g is not too small.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10875039)the Foundation of the Science and Technology of Hunan Province,China (Grant No. 2011CK3013)
文摘A variational-integral perturbation method(VIPM) is established by combining the variational perturbation with the integral perturbation.The first-order corrected wave functions are constructed,and the second-order energy corrections for the ground state and several lower excited states are calculated by applying the VIPM to the hydrogen atom in a strong uniform magnetic field.Our calculations demonstrated that the energy calculated by the VIPM only shows a negative value,which indicates that the VIPM method is more accurate than the other methods.Our study indicated that the VIPM can not only increase the accuracy of the results but also keep the convergence of the wave functions.
基金the Natural Science Foundation of China(No.22175191)Y.C.thanks the financial support from CAS-Croucher Funding Scheme for Joint Laboratories and Beijing Municipal Science&Technology Commission(No.Z211100007921020).
文摘While nickel(II)complexes have been widely used as catalysts for carbon-carbon coupling reactions,the exploration of their photophysical and photochemical properties is still in the infancy.Here,a series of square-planar Ni(II)complexes[(diNHC)NiX2]bearing chelating benzimidazole-based bis(N-heterocyclic carbene)ligands and varying anionic coligands(1,X=Cl;2,X=Br;3,X=I)are synthesized and structurally characterized.In solid state,both 1 and 2 exhibit orange-red photoluminescence under ambient conditions.The photophysical and electrochemical measurements along with density functional theory(DFT)calculations reveal that the low-energy emissions can be attributed to singlet excited states with ligand-to-ligand charge-transfer(LLCT)character.This work suggests that strong-field N-heterocyclic carbene ligands play a crucial role to achieve the luminescence of Ni(II)complexes.
基金the financial support of the Swiss National Science Foundation(SNSF),Project No.P2BEP2_191760.
文摘The purpose of this paper is to verify that the computational scheme from[Heid et al.,Gradient flow finite element discretizations with energy-based adaptivity for the Gross–Pitaevskii equation,J.Comput.Phys.436(2021)]for the numerical approximation of the ground state of the Gross–Pitaevskii equation can equally be applied for the effective approximation of excited states of Schr¨odinger’s equation.That procedure employs an adaptive interplay of a Sobolev gradient flow iteration and a novel local mesh refinement strategy,and yields a guaranteed energy decay in each step of the algorithm.The computational tests in the present work highlight that this strategy is indeed able to approximate excited states,with(almost)optimal convergence rate with respect to the number of degrees of freedom.
基金supported by the National Natural Science Foundation of China (22235006, 22122504, 51973162)the Foundation of Hubei Scientific Committee (2022BAA015)+1 种基金Wuhan city (whkxjsj014)the Fundamental Research Funds for the Central Universities (2042023kf2058)。
文摘Organic room temperature phosphorescence(RTP) materials with persistent afterglow exhibit good biocompatibility, high signal to noise ratio and time resolved imaging characteristics in bio-applications. Moreover, they can serve as hypoxia detection probes and photodynamic therapy agents for the sensitivity of triplet excitons toward oxygen in the surroundings. In this review, the recent progress of in vitro and in vivo afterglow bioimaging is presented by utilizing organic RTP materials. The strategies of molecular design and controlling methods of molecular packing were summarized, to prompt this new rising research field, with the emphasis on high intensity, ultralong lifetimes and red-shifted wavelengths of phosphorescence emission.
基金supported by the National Natural ScienceFoundation of China (Nos. 22173075, 21933012 and 31871877)the National Key R&D Program of China (No. 2017YFA0204902)+1 种基金the Fundamental Research Funds for the Central Universities(Nos. 20720200068 and 20720190002)the Beijing NationalLaboratory for Molecular Sciences (No. BNLMS202005).
文摘The investigation of electronic excited states in single-molecule junctions not only provides platforms to reveal the photophysical and photochemical processes at the molecular level,but also brings opportunities for the development of single-molecule optoelectronic devices.Understanding the interaction mechanisms between molecules and nanocavities is essential to obtain ondemand properties in devices by artificial design,since molecules in junctions exhibit unique behaviors of excited states benefited from the structures of metallic nanocavities.Here,we review the excitation mechanisms involved in the interplay between molecules and plasmonic nanocavities,and reveal the influence of nanostructures on excited-state properties by demonstrating the differences in excited state decay processes.Furthermore,vibronic transitions of molecules between nanoelectrodes are also discussed,offering a new single-molecule characterization method.Finally,we provide the potential applications and challenges in single-molecule optoelectronic devices and the possible directions in exploring the underlying mechanisms of photophysical and photochemical processes.
基金Supported by the 973 Program of China(2013 CB834402)National Natural Science Foundation of China(11275011,11535004)
文摘A cluster-transfer experiment of 9Be(gBe,14 C --+ a+lOBe)e: at an incident energy of 45 MeV was carried out in order to investigate the molecular structure in high-lying resonant states in 14C. This reaction is of extremely large Q-value, making it an excellent case to select the reaction mechanism and the final states in outgoing nuclei. The high-lying resonances in 14C are reconstructed for three sets of well discriminated final states in 10Be. The results confirm the previous decay measurements with clearly improved decay-channel selections and also show a new state at 23.5(1) MeV. The resonant states at 22.4(3) and 24.0(3) MeV decay primarily into the typical molecular states at about 6 MeV in 10Be, indicating a well developed cluster structure in these high-lying states in l4C. Further measurements of more states of this kind are suggested.
基金Project supported by the National Natural Science Foundation of China (Grant No. 12074295)。
文摘Expectation values of single electron and interelectronic geometric quantities such as <γ>,<γ_(12)> ,<γ_(<)> , <γ_(>)>,<cosθ_(12)> and <θ_(12)> are calculated for doubly excited 2pnp ^(1)P^(e)(3 ≤ n ≤ 5), 2pnp ^(3)P^(e)(2 ≤ n ≤ 5)and 2pnd ^(1,3)D°(3 ≤ n ≤ 5) states of helium using Hylleraas-B-spline basis set. The energy levels converge to at least 10 significant digits in our calculations.The extrapolated values of geometric quantities except for <θ_(12)> reach 10 significant digits as well;<θ_(12)> reaches at least 7 significant digits using a multipole expansion approach. Our results provide a precise reference for future research.