The low efficiency of photogenerated carrier separation,and the poor adsorption and activation ability of CO_(2)on the surface of photocatalyst were the key problems to limit the efficiency of photocatalytic CO_(2)red...The low efficiency of photogenerated carrier separation,and the poor adsorption and activation ability of CO_(2)on the surface of photocatalyst were the key problems to limit the efficiency of photocatalytic CO_(2)reduction.Hence,maximally accelerating the immigration of photogenerated charges d increasing the number of active sites are critical points to boost the overall performance of photocatalytic CO_(2)reduction.However,it is still huge challenge.In this work,the Ni-doped ultrathin Bi_(4)O_(5)Br_(2)nanosheets,which was successfully prepared by hydrothermal and ultrasonic chemical stripping methods,exhibited efficient photocatalytic conversion of CO_(2)to CO.The results of experiments and theoretical calculations indicated that the doped Ni^(2+)significantly increased the crystal dipole moment of Bi_(4)O_(5)Br_(2)in y direction(from 0 to 0.096 e?),which enhanced the polarized electric field strength inside Bi_(4)O_(5)Br_(2),and further promoted the immigration of photogenerated carriers.Meanwhile,the ultrathin structure and doped Ni^(2+)synergistically increased the number of active sites,thereby promoting the adsorption and activation of CO_(2)molecules,as evidenced by experimental and theoretical results collectively.As result,The CO yield was as high as 26.57μmol g–1 h–1 for the prepared Ni-doped ultrathin Bi_(4)O_(5)Br_(2)nanosheets under full spectrum light irradiation,which was 9.48 times that of Bi_(4)O_(5)Br_(2).Therefore,it is of great scientific significance in this study to explore strategies to promote the separation of photogenerated carriers and enhance the adsorption and activation ability of CO_(2)on the surface.展开更多
In this work, we have applied the translation invariant shell model with number of quanta of excitations N=2,4,6,8and 10 to define the ground-state eigenenergies and their corresponding normalized eigenstates, the roo...In this work, we have applied the translation invariant shell model with number of quanta of excitations N=2,4,6,8and 10 to define the ground-state eigenenergies and their corresponding normalized eigenstates, the root mean-square radius, and the magnetic dipole moment of the nucleus 6Li. We have computed the necessary two-particle orbital fractional parentage coefficients for nuclei with mass number A=6and number of quanta of excitations N=10, which are not available in the literature. In addition, we have used our previous findings on the nucleon-nucleon interaction with Gaussian radial dependencies, which fits the deuteron characteristics as well as the triton binding energy, root-mean square radius and magnetic dipole moment. The numerical results obtained in this work are in excellent agreement with the corresponding experimental data and the previously published theoretical results in the literature.展开更多
Dielectrophoresis （DEP） is one of the most popular techniques for bio-particle manipulation in microfluidic systems. Traditional calculation of dielectrophoretic forces of single particle based on the approximation ...Dielectrophoresis （DEP） is one of the most popular techniques for bio-particle manipulation in microfluidic systems. Traditional calculation of dielectrophoretic forces of single particle based on the approximation of equivalent dipole moment （EDM） cannot be directly applied on the dense particle interactions in an electrical field. The Maxwell stress tensor （MST） method is strictly accurate in the theory for dielectrophoretic forces of particle interaction, but the cumbersome and complicated numerical computation greatly limits its practical applications. A novel iterative dipole moment （IDM） method is pre- sented in this work for calculating the dielectrophoretic forces of particle-particle inter- actions. The accuracy, convergence, and simplicity of the IDM are confirmed by a series of examples of two-particle interaction in a DC/AC electrical field. The results indicate that the IDM is able to calculate the DEP particle interaction forces in good agreement with the MST method. The IDM is a purely analytical operation and does not require complicated numerical computation for solving the differential equations of an electrical field while the particle is moving.展开更多
Single-crystal X-ray diffraction structural data of four Fe-Mg tourmalines with different Fe contents from Xinjiang, Sichuan, and Yunnan Provinces, China, were collected at room temperature and-100oC. The intrinsic di...Single-crystal X-ray diffraction structural data of four Fe-Mg tourmalines with different Fe contents from Xinjiang, Sichuan, and Yunnan Provinces, China, were collected at room temperature and-100oC. The intrinsic dipole moments of polyhedra and the total intrinsic dipole moment of the unit cell were calculated. By comparing the intrinsic electric dipole moments of the X, Y, Z, T, and B site polyhedra, it is found that the T site polyhedron makes the greatest contribution to the total intrinsic dipole moment. The pyroelectric coefficients of four Fe-Mg tourmalines were experimentally determined, and the influence of intrinsic dipole moments on their pyroelectric properties was inves-tigated. The experimental results show that, compared with the case at room temperature, the intrinsic dipole moments change with the total Fe content at-100oC in a completely different way. With the decrease of temperature, the total intrinsic dipole moments of tourmaline de-crease. Over the same temperature interval, the pyroelectric coefficients increase with the increase in intrinsic dipole moment.展开更多
Stretching vibrational band intensities of XH3 （X=N, Sb） molecules are investigated employing three-dimensional dipole moment surfaces combined with the local mode Hamiltonian model. The dipole moment surfaces of NH...Stretching vibrational band intensities of XH3 （X=N, Sb） molecules are investigated employing three-dimensional dipole moment surfaces combined with the local mode Hamiltonian model. The dipole moment surfaces of NH3 and SbH3 are calculated with the density functional theory and at the correlated MP2 level, respectively. The calculated band intensities are in good agreement with the available experimental data. The contribution to the band intensities from the different terms in the polynomial expansion of the dipole moments of four group V hydrides （NH3, PH3, AsH3 and SbH3） are discussed. It is concluded that the breakdown of the bond dipole approximation must be considered. The intensity “borrowing” effect due to the wave function mixing among the stretching vibrational states is found to be less significant for the molecules that reach the local mode limit.展开更多
Steady-state absorption and fluorescence spectra, and time-resolved fluorescence spectra of coumarin 343 （C343） were measured in different solvents. The effect of the solvent on the spectral properties and dipole mo...Steady-state absorption and fluorescence spectra, and time-resolved fluorescence spectra of coumarin 343 （C343） were measured in different solvents. The effect of the solvent on the spectral properties and dipole moment of the lowest excited state of C343 were investigated. It was found that the absorption and fluorescence spectra red-shifted slightly and strongly with increasing solvent polarity, respectively, because the charge distribution of the excited state leaded to the increasing difference between the absorption and fluorescence spectra with increasing solvent polarity. The dipole moment of the lowest excited state of C343 was determined from solvatochromic measurements and the quantum chemical calculation, and the results obtained from these two methods were fully consistent. Investigations of the time-resolved fluorescence of C343 in different solvents indicated that the fluorescence lifetimes increased nearly linearly with 4.45 ns in water. This can be ascribed between C343 and hydrogen donating increasing solvent polarity from 3.09 ns in toluene to to the intermolecular hydrogen bonding interactions solvents展开更多
The reasonable dissociation limit of the A^1∑＋ state ^7LiH molecule is obtained. The accurate dissociation energy and the equilibrium geometry of this state are calculated using a symmetry-adapted-cluster configurat...The reasonable dissociation limit of the A^1∑＋ state ^7LiH molecule is obtained. The accurate dissociation energy and the equilibrium geometry of this state are calculated using a symmetry-adapted-cluster configuration-interaction method in complete active space for the first time, The whole potential energy curve and the dipole moment function for the A^1∑＋ state are calculated over a wide internuclear separation range from about 0.1 to 1.4 nm. The calculated equilibrium geometry and dissociation energy of this potential energy curve are of Re=0.2487 nm and De=1.064eV, respectively. The unusual negative values of the anharmonicity constant and the vibration-rotational coupling constant are of ωeXe=-4.7158cm^-1 and αe=0.08649cm^-1, respectively. The vertical excitation energy from the ground to the A^1∑＋ state is calculated and the value is of 3.613eV at 0.15875nm （the equilibrium position of the ground state）. The highly anomalous shape of this potential energy curve, which is exceptionally flat over a wide radial range around the equilibrium position, is discussed in detail. The harmonic frequency value of 502.47cm^-1 about this state is approximately estimated. Careful comparison of the theoretical determinations with those obtained by previous theories about the A^1∑＋ state dissociation energy clearly shows that the present calculations are much closer to the experiments than previous theories, thus represents an improvement.展开更多
We report a sensitive detection of high Rydberg atom with large dipole moment utilizing its deflection near a pair of parallel cylindrical copper rods which are oppositely charged. When the low-field seeking state Ryd...We report a sensitive detection of high Rydberg atom with large dipole moment utilizing its deflection near a pair of parallel cylindrical copper rods which are oppositely charged. When the low-field seeking state Rydberg atoms fly across the gradient electric field formed by the pair of rods, they will be pushed away from the rods while the high-field seeking state ones will be attracted towards the rods. These atoms will form different patterns on an ion imaging system placed downwards at the end of the rods. The spatial distribution of the deflected atoms on the imaging system is also simulated, in good agreement with the experimental results, from which we can deduce the quantum state information of the excited atoms. This state resolvable Rydberg atom detection can be used for the dynamics research of the dipole-dipole interaction between atoms with large dipole moments.展开更多
The quantum phase effects for induced electric and magnetic dipole moments are investigated. It is shown that the phase shift received by the induced electric dipole has the same form as the one induced by magnetic di...The quantum phase effects for induced electric and magnetic dipole moments are investigated. It is shown that the phase shift received by the induced electric dipole has the same form as the one induced by magnetic dipole moment, therefore the total phase is a hybrid of these two types of phase. This feature indicates that to have a decisive measurement on either one of these two phases, it is necessary to measure the velocity dependence of the observed phase.展开更多
The mean-square radius of gyration <S^2>,the mean-square dipole moment <D^2>,the mean-square end-to-end distance <R^2> and their temperature coefficients of unsymmetrical disubstituted poly(methylphe...The mean-square radius of gyration <S^2>,the mean-square dipole moment <D^2>,the mean-square end-to-end distance <R^2> and their temperature coefficients of unsymmetrical disubstituted poly(methylphenylsiloxane) (PMPS) chains, as a function of stereochemical structure,confomational energies and length of polymers,were studied by using an improved configurational-confomational statistical method based on the rotational-isomeric-state theory.It is found that the increase in isotacticity of P...展开更多
An ab initio calculations on the ground and low-lying excited statesX2∑＋,2^2∑＋,3^2∑＋,1^4∏,2^4∏,1^4∑＋,2^4∑＋,and 3^4∑＋of KBe molecule have been performed using multireference configuration interaction （M...An ab initio calculations on the ground and low-lying excited statesX2∑＋,2^2∑＋,3^2∑＋,1^4∏,2^4∏,1^4∑＋,2^4∑＋,and 3^4∑＋of KBe molecule have been performed using multireference configuration interaction （MRCI） plus Davidsoncorrections （MRCI＋Q） approach with all electron basis set aug-cc-pCV5Z-DK for Be and def2-AQZVPP-JKFI for K.3^2∑＋,1^4∏,2^4∏,1^4∑＋,2^4∑＋and3^4∑＋states are investigated for the first time. Inner shell electron correlations are computed on the potential energy curves （PECs） calculations. The spectroscopic and molecular parameters are also predicted. In addition, The transition properties including transition dipole moment, Franck-Condon factors qv′v″, Einstein coefficients Av′v″, and the radiative lifetimesτ′for the2^2∑＋-X2∑＋,3^2∑＋-X2∑＋,and 2^4∏-1^4∏ transitions are predictedat the same time.展开更多
Recently, the diverse properties of Rydberg atoms, which probably arise from its large electric dipole moment （EDM）, have been explored. In this paper, we report electric dipole moments along with Stark energies and...Recently, the diverse properties of Rydberg atoms, which probably arise from its large electric dipole moment （EDM）, have been explored. In this paper, we report electric dipole moments along with Stark energies and charge densities of lithium Rydberg states in the presence of electric fields, calculated by matrix diagonalization. Huge electric dipole moments are discovered. In order to check the validity of the EDMs, we also use these electric dipole moments to calculate the Stark energies by numerical integration. The results agree with those calculated by matrix diagonalization.展开更多
A dressed-state perturbation theory beyond the rotating wave approximation （RWA） is presented to investigate the interaction between a two-level electronic transition of polar molecules and a quantized cavity field....A dressed-state perturbation theory beyond the rotating wave approximation （RWA） is presented to investigate the interaction between a two-level electronic transition of polar molecules and a quantized cavity field. Analytical expressions can be explicitly derived for both the ground- and excited-state-energy spectrums and wave functions of the system, where the contribution of permanent dipole moments （PDM） and the counter-rotating wave term （CRT） can be shown separately. The validity of these explicit results is discussed by comparison with the direct numerical simulation. Compared to the CRT coupling, PDM results in the coupling of more dressed states and the energy shift is proportional to the square of the normalized permanent dipole difference, and a greater Bloch-Siegert shift can be produced in the giant dipole molecule cavity QED. In addition, our method can also be extended to the solution of the two-level atom Rabi model Hamiltonian beyond the RWA.展开更多
An accurate electric dipole moment function(EDMF) is obtained for the carbon monoxide(CO) molecule(X1+Σ)by fitting the experimental rovibrational transitional moments. Additionally, an accurate ab initio EDMF is foun...An accurate electric dipole moment function(EDMF) is obtained for the carbon monoxide(CO) molecule(X1+Σ)by fitting the experimental rovibrational transitional moments. Additionally, an accurate ab initio EDMF is found using the highly accurate, multi-reference averaged coupled-pair functional(ACPF) approach with the basis set, aug-cc-p V6 Z, and a finite-field with ±0.005 a.u.(The unit a.u. is the abbreviation of atomic unit). This ab initio EDMF is very consistent with the fitted ones. The vibrational transition matrix moments and the Herman–Wallis factors, calculated with the Rydberg–Klein–Rees(RKR) potential and the fitted and ab initio EDMFs, are compared with experimental measurements. The consistency of these line intensities with the high-resolution transmission(HITRAN) molecular database demonstrates the improved accuracy of the fitted and ab initio EDMFs derived in this work.展开更多
Recently,more attention have been paid on the construction of dipole moment functions(DMF)using theoretical methods.However,the computational methods to construct DMFs are not validated as much as those for potential ...Recently,more attention have been paid on the construction of dipole moment functions(DMF)using theoretical methods.However,the computational methods to construct DMFs are not validated as much as those for potential energy surfaces do.In this letter,using Ar…He as an example,we tested how spectroscopyaccuracy DMFs can be constructed using ab initio methods.We especially focused on the basis set dependency in this scenario,i.e.,the convergence of DMF with the sizes of basis sets,basis set superposition error,and mid-bond functions.We also tested the explicitly correlated method,which converges with smaller basis sets than the conventional methods do.This work can serve as a pictorial sample of all these computational technologies behaving in the context of constructing DMFs.展开更多
The transition dipole moments（TDMs） of ultracold85 Rb133 Cs molecules between the lowest vibrational ground level, （X^1Σ~＋（ v= 0, J= 1）, and the two excited rovibrational levels, 2~3Π0＋（v′= 10, J′= 2） and...The transition dipole moments（TDMs） of ultracold85 Rb133 Cs molecules between the lowest vibrational ground level, （X^1Σ~＋（ v= 0, J= 1）, and the two excited rovibrational levels, 2~3Π0＋（v′= 10, J′= 2） and 2~1Π1（v′= 22,J′= 2）, are measured using depletion spectroscopy. The ground-state85 Rb133 Cs molecules are formed from cold mixed component atoms via the 2~3Π0-（ v= 11, J= 0） short-range level, then detected by time-of-flight mass spectrum. A home-made external-cavity diode laser is used as the depletion laser to couple the ground level and the two excited levels. Based on the depletion spectroscopy, the corresponding TDMs are then derived to be 3.5（2）×10^（-3）eαα and 1.6（1）×10^（-2）eαα, respectively, where 0）（60 represents the atomic unit of electric dipole moment. The enhance of TDM with nearly a factor of 5 for the 21Π1（v′= 22, J′= 2） excited level means that it has stronger coupling with the ground level. It is meaningful to find more levels with much more strong coupling strength by the represented depletion spectroscopy to realize direct stimulated Raman adiabatic passage transfer from scattering atomic states to deeply molecular states.展开更多
Experimental vibrational spectra of heavy light XH stretching vibrations of simple molecules have been analyzed using the local mode model.In addition,the bond dipole approach,which assumes that the transition dipole ...Experimental vibrational spectra of heavy light XH stretching vibrations of simple molecules have been analyzed using the local mode model.In addition,the bond dipole approach,which assumes that the transition dipole moment(TDM)of the XH stretching mode is aligned along the XH bond,has helped analyze experimental spectra.We performed theoretical calculations of the XH stretching vibrations of HOD,HND^−,HCD,HSD,HPD^−,and HSiD using local mode model and multi-dimensional normal modes.We found that consistent with previous notions,a localized 1D picture to treat the XH stretching vibration is valid even for analyzing the TDM tilt angle.In addition,while the TDM of the OH stretching fundamental transition tilted away from the OH bond in the direction away from the OD bond,that for the XH stretching fundamental of HSD,HND^−,HPD^−,HCD,and HSiD tilted away from the OH bond but toward the OD bond.This shows that bond dipole approximation may not be a good approximation for the present systems and that the heavy atom X can affect the transition dipole moment direction.The variation of the dipole moment was analyzed using the atoms-in-molecule method.展开更多
The coherent exciton plays an important role in the photosynthetic primary process, and its functions are deeply dependent on the orientation arrangements of local transition dipole moments （TDMs）. We theoretically ...The coherent exciton plays an important role in the photosynthetic primary process, and its functions are deeply dependent on the orientation arrangements of local transition dipole moments （TDMs）. We theoretically and systematically study the physical property of the coherent exciton at different orientation arrangements of the local TDMs in circular light-harvesting （LH） complexes. Especially, if the orientation arrangements are different, the delocalized TDMs of the coherent excitons and the energy locations of the optically active coherent excitons （OACEs） can be obviously different, and then there are more manners to capture, store and transfer light energy in and between LH complexes. Similarly, if the orientation arrangements are altered, light absorption and radiative intensities can be converted fully between the OACEs in the upper and lower coherent exciton bands, and then the blue and red shifts of the absorption and radiative bands of the pigment molecules can occur simultaneously at some orientation arrangements. If the systems are in the vicinities of the critical orientation arrangements, the weak static disorder or small thermal excitation can destroy the coherent electronic excitations, and then the coherent exciton cannot exist any more.展开更多
The littlest Higgs model with T-parity, which is called LHT model, predicts the existence of the new particles, such as heavy top quarks, heavy gauge bosons, and mirror fermions. We calculate the one-loop contribution...The littlest Higgs model with T-parity, which is called LHT model, predicts the existence of the new particles, such as heavy top quarks, heavy gauge bosons, and mirror fermions. We calculate the one-loop contributions of these new particles to the top quark ehromomagnetic dipole moment （CMDM） AK. We find that the contribution of the LHT model is one order of magnitude smaller than the standard model prediction value.展开更多
Molecular dipole moments computed at the levels of HF/STO-3G, HF/6-31G(d, p), HF/6-311+G(2d, 2p), MP2/6-31G(d, p) and MP2/6-311+G(2d, 2p) have been investigated. HF/6-311+G(2d, 2p) was found to be the relatively good ...Molecular dipole moments computed at the levels of HF/STO-3G, HF/6-31G(d, p), HF/6-311+G(2d, 2p), MP2/6-31G(d, p) and MP2/6-311+G(2d, 2p) have been investigated. HF/6-311+G(2d, 2p) was found to be the relatively good choice to compute MKS charges for reproducing the experimental values of molecular dipole moments. Root mean square deviation of computed dipole moments for 21 small polar molecules is about 0.1969 D.展开更多
文摘The low efficiency of photogenerated carrier separation,and the poor adsorption and activation ability of CO_(2)on the surface of photocatalyst were the key problems to limit the efficiency of photocatalytic CO_(2)reduction.Hence,maximally accelerating the immigration of photogenerated charges d increasing the number of active sites are critical points to boost the overall performance of photocatalytic CO_(2)reduction.However,it is still huge challenge.In this work,the Ni-doped ultrathin Bi_(4)O_(5)Br_(2)nanosheets,which was successfully prepared by hydrothermal and ultrasonic chemical stripping methods,exhibited efficient photocatalytic conversion of CO_(2)to CO.The results of experiments and theoretical calculations indicated that the doped Ni^(2+)significantly increased the crystal dipole moment of Bi_(4)O_(5)Br_(2)in y direction(from 0 to 0.096 e?),which enhanced the polarized electric field strength inside Bi_(4)O_(5)Br_(2),and further promoted the immigration of photogenerated carriers.Meanwhile,the ultrathin structure and doped Ni^(2+)synergistically increased the number of active sites,thereby promoting the adsorption and activation of CO_(2)molecules,as evidenced by experimental and theoretical results collectively.As result,The CO yield was as high as 26.57μmol g–1 h–1 for the prepared Ni-doped ultrathin Bi_(4)O_(5)Br_(2)nanosheets under full spectrum light irradiation,which was 9.48 times that of Bi_(4)O_(5)Br_(2).Therefore,it is of great scientific significance in this study to explore strategies to promote the separation of photogenerated carriers and enhance the adsorption and activation ability of CO_(2)on the surface.
文摘In this work, we have applied the translation invariant shell model with number of quanta of excitations N=2,4,6,8and 10 to define the ground-state eigenenergies and their corresponding normalized eigenstates, the root mean-square radius, and the magnetic dipole moment of the nucleus 6Li. We have computed the necessary two-particle orbital fractional parentage coefficients for nuclei with mass number A=6and number of quanta of excitations N=10, which are not available in the literature. In addition, we have used our previous findings on the nucleon-nucleon interaction with Gaussian radial dependencies, which fits the deuteron characteristics as well as the triton binding energy, root-mean square radius and magnetic dipole moment. The numerical results obtained in this work are in excellent agreement with the corresponding experimental data and the previously published theoretical results in the literature.
基金Project supported by the National Natural Science Foundation of China(No.11172111)
文摘Dielectrophoresis （DEP） is one of the most popular techniques for bio-particle manipulation in microfluidic systems. Traditional calculation of dielectrophoretic forces of single particle based on the approximation of equivalent dipole moment （EDM） cannot be directly applied on the dense particle interactions in an electrical field. The Maxwell stress tensor （MST） method is strictly accurate in the theory for dielectrophoretic forces of particle interaction, but the cumbersome and complicated numerical computation greatly limits its practical applications. A novel iterative dipole moment （IDM） method is pre- sented in this work for calculating the dielectrophoretic forces of particle-particle inter- actions. The accuracy, convergence, and simplicity of the IDM are confirmed by a series of examples of two-particle interaction in a DC/AC electrical field. The results indicate that the IDM is able to calculate the DEP particle interaction forces in good agreement with the MST method. The IDM is a purely analytical operation and does not require complicated numerical computation for solving the differential equations of an electrical field while the particle is moving.
基金financially supported by the National Natural Science Foundation of China(No.40672031)
文摘Single-crystal X-ray diffraction structural data of four Fe-Mg tourmalines with different Fe contents from Xinjiang, Sichuan, and Yunnan Provinces, China, were collected at room temperature and-100oC. The intrinsic dipole moments of polyhedra and the total intrinsic dipole moment of the unit cell were calculated. By comparing the intrinsic electric dipole moments of the X, Y, Z, T, and B site polyhedra, it is found that the T site polyhedron makes the greatest contribution to the total intrinsic dipole moment. The pyroelectric coefficients of four Fe-Mg tourmalines were experimentally determined, and the influence of intrinsic dipole moments on their pyroelectric properties was inves-tigated. The experimental results show that, compared with the case at room temperature, the intrinsic dipole moments change with the total Fe content at-100oC in a completely different way. With the decrease of temperature, the total intrinsic dipole moments of tourmaline de-crease. Over the same temperature interval, the pyroelectric coefficients increase with the increase in intrinsic dipole moment.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 20103007 and 20473079）.
文摘Stretching vibrational band intensities of XH3 （X=N, Sb） molecules are investigated employing three-dimensional dipole moment surfaces combined with the local mode Hamiltonian model. The dipole moment surfaces of NH3 and SbH3 are calculated with the density functional theory and at the correlated MP2 level, respectively. The calculated band intensities are in good agreement with the available experimental data. The contribution to the band intensities from the different terms in the polynomial expansion of the dipole moments of four group V hydrides （NH3, PH3, AsH3 and SbH3） are discussed. It is concluded that the breakdown of the bond dipole approximation must be considered. The intensity “borrowing” effect due to the wave function mixing among the stretching vibrational states is found to be less significant for the molecules that reach the local mode limit.
文摘Steady-state absorption and fluorescence spectra, and time-resolved fluorescence spectra of coumarin 343 （C343） were measured in different solvents. The effect of the solvent on the spectral properties and dipole moment of the lowest excited state of C343 were investigated. It was found that the absorption and fluorescence spectra red-shifted slightly and strongly with increasing solvent polarity, respectively, because the charge distribution of the excited state leaded to the increasing difference between the absorption and fluorescence spectra with increasing solvent polarity. The dipole moment of the lowest excited state of C343 was determined from solvatochromic measurements and the quantum chemical calculation, and the results obtained from these two methods were fully consistent. Investigations of the time-resolved fluorescence of C343 in different solvents indicated that the fluorescence lifetimes increased nearly linearly with 4.45 ns in water. This can be ascribed between C343 and hydrogen donating increasing solvent polarity from 3.09 ns in toluene to to the intermolecular hydrogen bonding interactions solvents
基金Project supported by the National Natural Science Foundation of China （Grant No 10174019）, the Natural Science Foundation of Henan Province, China （Grant No 2006,140008） and Henan Innovation for University Prominent Research Talents （Grant No 2006KYCX002）.Acknowledgement We heartily thank Professor Zhu Zheng-He at Sichuan University for his helpful discussion about the reasonable dissociation limits during the planning stage of these calculations.
文摘The reasonable dissociation limit of the A^1∑＋ state ^7LiH molecule is obtained. The accurate dissociation energy and the equilibrium geometry of this state are calculated using a symmetry-adapted-cluster configuration-interaction method in complete active space for the first time, The whole potential energy curve and the dipole moment function for the A^1∑＋ state are calculated over a wide internuclear separation range from about 0.1 to 1.4 nm. The calculated equilibrium geometry and dissociation energy of this potential energy curve are of Re=0.2487 nm and De=1.064eV, respectively. The unusual negative values of the anharmonicity constant and the vibration-rotational coupling constant are of ωeXe=-4.7158cm^-1 and αe=0.08649cm^-1, respectively. The vertical excitation energy from the ground to the A^1∑＋ state is calculated and the value is of 3.613eV at 0.15875nm （the equilibrium position of the ground state）. The highly anomalous shape of this potential energy curve, which is exceptionally flat over a wide radial range around the equilibrium position, is discussed in detail. The harmonic frequency value of 502.47cm^-1 about this state is approximately estimated. Careful comparison of the theoretical determinations with those obtained by previous theories about the A^1∑＋ state dissociation energy clearly shows that the present calculations are much closer to the experiments than previous theories, thus represents an improvement.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.91421305,91121005,and 11674359)the National Key Basic Research Program of China(Grant No.2013CB922003)
文摘We report a sensitive detection of high Rydberg atom with large dipole moment utilizing its deflection near a pair of parallel cylindrical copper rods which are oppositely charged. When the low-field seeking state Rydberg atoms fly across the gradient electric field formed by the pair of rods, they will be pushed away from the rods while the high-field seeking state ones will be attracted towards the rods. These atoms will form different patterns on an ion imaging system placed downwards at the end of the rods. The spatial distribution of the deflected atoms on the imaging system is also simulated, in good agreement with the experimental results, from which we can deduce the quantum state information of the excited atoms. This state resolvable Rydberg atom detection can be used for the dynamics research of the dipole-dipole interaction between atoms with large dipole moments.
基金Supported by the China Scholarship Councilthe Hanjiang Scholar Project of Shaanxi University of Technology
文摘The quantum phase effects for induced electric and magnetic dipole moments are investigated. It is shown that the phase shift received by the induced electric dipole has the same form as the one induced by magnetic dipole moment, therefore the total phase is a hybrid of these two types of phase. This feature indicates that to have a decisive measurement on either one of these two phases, it is necessary to measure the velocity dependence of the observed phase.
基金supported by the National Basic Research Program (973) of China (No.10574109)the Zhejiang Provincial Science and Technology Department (No.2007G60G1120019)+1 种基金National Science Foundation of Zhejiang Province (No.Y604064)Zhejiang Gongshang University (No.08-13),China.
文摘The mean-square radius of gyration <S^2>,the mean-square dipole moment <D^2>,the mean-square end-to-end distance <R^2> and their temperature coefficients of unsymmetrical disubstituted poly(methylphenylsiloxane) (PMPS) chains, as a function of stereochemical structure,confomational energies and length of polymers,were studied by using an improved configurational-confomational statistical method based on the rotational-isomeric-state theory.It is found that the increase in isotacticity of P...
基金Project supported by the National Natural Science Foundation of China(Grant No.11647075)the Scientific Research Fund of Sichuan Provincial Education Department,China(Grant No.14ZB0284)the Scientific Research Key Project of Yibin University,China(Grant No.2013QD09)
文摘An ab initio calculations on the ground and low-lying excited statesX2∑＋,2^2∑＋,3^2∑＋,1^4∏,2^4∏,1^4∑＋,2^4∑＋,and 3^4∑＋of KBe molecule have been performed using multireference configuration interaction （MRCI） plus Davidsoncorrections （MRCI＋Q） approach with all electron basis set aug-cc-pCV5Z-DK for Be and def2-AQZVPP-JKFI for K.3^2∑＋,1^4∏,2^4∏,1^4∑＋,2^4∑＋and3^4∑＋states are investigated for the first time. Inner shell electron correlations are computed on the potential energy curves （PECs） calculations. The spectroscopic and molecular parameters are also predicted. In addition, The transition properties including transition dipole moment, Franck-Condon factors qv′v″, Einstein coefficients Av′v″, and the radiative lifetimesτ′for the2^2∑＋-X2∑＋,3^2∑＋-X2∑＋,and 2^4∏-1^4∏ transitions are predictedat the same time.
基金supported by the National Basic Research Program of China(Grant No.2012CB921603)the National Natural Science Foundation of China(GrantNos.61378039,61078013,61178009,and 11274209)+3 种基金the Program for Changjiang Scholars and Innovative Research Team in University,China(Grant No.IRT13076)the Fund for Fostering Talents in Basic Science of the National Natural Science Foundation of China(Grant No.J1210036)the Natural Science Foundation of Shanxi Province,China(Grant No.2012011003-2)the Shanxi International Collaboration Program,China(Grant No.2010081046)
文摘Recently, the diverse properties of Rydberg atoms, which probably arise from its large electric dipole moment （EDM）, have been explored. In this paper, we report electric dipole moments along with Stark energies and charge densities of lithium Rydberg states in the presence of electric fields, calculated by matrix diagonalization. Huge electric dipole moments are discovered. In order to check the validity of the EDMs, we also use these electric dipole moments to calculate the Stark energies by numerical integration. The results agree with those calculated by matrix diagonalization.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB01010200)the Hundred Talents Program of the Chinese Academy of Sciences(Grant No.Y321311401)+2 种基金the National Natural Science Foundation of China(Grant Nos.61475139,11347147,and11247014)the National Basics Research Program of China(Grant No.2013CB329501)the Zhejiang Provincial Natural Science Foundation(Grant No.LQ13A040006)
文摘A dressed-state perturbation theory beyond the rotating wave approximation （RWA） is presented to investigate the interaction between a two-level electronic transition of polar molecules and a quantized cavity field. Analytical expressions can be explicitly derived for both the ground- and excited-state-energy spectrums and wave functions of the system, where the contribution of permanent dipole moments （PDM） and the counter-rotating wave term （CRT） can be shown separately. The validity of these explicit results is discussed by comparison with the direct numerical simulation. Compared to the CRT coupling, PDM results in the coupling of more dressed states and the energy shift is proportional to the square of the normalized permanent dipole difference, and a greater Bloch-Siegert shift can be produced in the giant dipole molecule cavity QED. In addition, our method can also be extended to the solution of the two-level atom Rabi model Hamiltonian beyond the RWA.
基金supported by the National Natural Science Foundation of China(Grant Nos.11374217 and 11474207)
文摘An accurate electric dipole moment function(EDMF) is obtained for the carbon monoxide(CO) molecule(X1+Σ)by fitting the experimental rovibrational transitional moments. Additionally, an accurate ab initio EDMF is found using the highly accurate, multi-reference averaged coupled-pair functional(ACPF) approach with the basis set, aug-cc-p V6 Z, and a finite-field with ±0.005 a.u.(The unit a.u. is the abbreviation of atomic unit). This ab initio EDMF is very consistent with the fitted ones. The vibrational transition matrix moments and the Herman–Wallis factors, calculated with the Rydberg–Klein–Rees(RKR) potential and the fitted and ab initio EDMFs, are compared with experimental measurements. The consistency of these line intensities with the high-resolution transmission(HITRAN) molecular database demonstrates the improved accuracy of the fitted and ab initio EDMFs derived in this work.
基金supported by the National Natural Science Foundation of China(No.21533003,No.21773081 and No.22073035)。
文摘Recently,more attention have been paid on the construction of dipole moment functions(DMF)using theoretical methods.However,the computational methods to construct DMFs are not validated as much as those for potential energy surfaces do.In this letter,using Ar…He as an example,we tested how spectroscopyaccuracy DMFs can be constructed using ab initio methods.We especially focused on the basis set dependency in this scenario,i.e.,the convergence of DMF with the sizes of basis sets,basis set superposition error,and mid-bond functions.We also tested the explicitly correlated method,which converges with smaller basis sets than the conventional methods do.This work can serve as a pictorial sample of all these computational technologies behaving in the context of constructing DMFs.
基金Supported by the National Key Research and Development Program of China under Grant No 2017YFA0304203the National Natural Science Foundation of China under Grant Nos 61675120 and 11434007+3 种基金the National Natural Science Foundation of China for Excellent Research Team under Grant No 61121064the Shanxi Scholarship Council of China,the 1331KSCthe PCSIRT under Grant No IRT13076the Applied Basic Research Project of Shanxi Province under Grant No 201601D202008
文摘The transition dipole moments（TDMs） of ultracold85 Rb133 Cs molecules between the lowest vibrational ground level, （X^1Σ~＋（ v= 0, J= 1）, and the two excited rovibrational levels, 2~3Π0＋（v′= 10, J′= 2） and 2~1Π1（v′= 22,J′= 2）, are measured using depletion spectroscopy. The ground-state85 Rb133 Cs molecules are formed from cold mixed component atoms via the 2~3Π0-（ v= 11, J= 0） short-range level, then detected by time-of-flight mass spectrum. A home-made external-cavity diode laser is used as the depletion laser to couple the ground level and the two excited levels. Based on the depletion spectroscopy, the corresponding TDMs are then derived to be 3.5（2）×10^（-3）eαα and 1.6（1）×10^（-2）eαα, respectively, where 0）（60 represents the atomic unit of electric dipole moment. The enhance of TDM with nearly a factor of 5 for the 21Π1（v′= 22, J′= 2） excited level means that it has stronger coupling with the ground level. It is meaningful to find more levels with much more strong coupling strength by the represented depletion spectroscopy to realize direct stimulated Raman adiabatic passage transfer from scattering atomic states to deeply molecular states.
文摘Experimental vibrational spectra of heavy light XH stretching vibrations of simple molecules have been analyzed using the local mode model.In addition,the bond dipole approach,which assumes that the transition dipole moment(TDM)of the XH stretching mode is aligned along the XH bond,has helped analyze experimental spectra.We performed theoretical calculations of the XH stretching vibrations of HOD,HND^−,HCD,HSD,HPD^−,and HSiD using local mode model and multi-dimensional normal modes.We found that consistent with previous notions,a localized 1D picture to treat the XH stretching vibration is valid even for analyzing the TDM tilt angle.In addition,while the TDM of the OH stretching fundamental transition tilted away from the OH bond in the direction away from the OD bond,that for the XH stretching fundamental of HSD,HND^−,HPD^−,HCD,and HSiD tilted away from the OH bond but toward the OD bond.This shows that bond dipole approximation may not be a good approximation for the present systems and that the heavy atom X can affect the transition dipole moment direction.The variation of the dipole moment was analyzed using the atoms-in-molecule method.
基金project supported by the National Natural Science Foundation of China （Grant Nos 60438020 and 60321003）, and the Knowledge innovation program of the Chinese Academy of Sciences （Grant No KJCX2-SW-W14）.
文摘The coherent exciton plays an important role in the photosynthetic primary process, and its functions are deeply dependent on the orientation arrangements of local transition dipole moments （TDMs）. We theoretically and systematically study the physical property of the coherent exciton at different orientation arrangements of the local TDMs in circular light-harvesting （LH） complexes. Especially, if the orientation arrangements are different, the delocalized TDMs of the coherent excitons and the energy locations of the optically active coherent excitons （OACEs） can be obviously different, and then there are more manners to capture, store and transfer light energy in and between LH complexes. Similarly, if the orientation arrangements are altered, light absorption and radiative intensities can be converted fully between the OACEs in the upper and lower coherent exciton bands, and then the blue and red shifts of the absorption and radiative bands of the pigment molecules can occur simultaneously at some orientation arrangements. If the systems are in the vicinities of the critical orientation arrangements, the weak static disorder or small thermal excitation can destroy the coherent electronic excitations, and then the coherent exciton cannot exist any more.
基金supported in part by the Program for New Century Excellent Talents in Universities under Grant No.NCET-04-0290National Natural Science Foundation of China under Grant No.10675057
文摘The littlest Higgs model with T-parity, which is called LHT model, predicts the existence of the new particles, such as heavy top quarks, heavy gauge bosons, and mirror fermions. We calculate the one-loop contributions of these new particles to the top quark ehromomagnetic dipole moment （CMDM） AK. We find that the contribution of the LHT model is one order of magnitude smaller than the standard model prediction value.
基金The project was supported by the National Science Foundation (29773021) Provincial Educational Foundation of Jiangsu (98KJB150001).
文摘Molecular dipole moments computed at the levels of HF/STO-3G, HF/6-31G(d, p), HF/6-311+G(2d, 2p), MP2/6-31G(d, p) and MP2/6-311+G(2d, 2p) have been investigated. HF/6-311+G(2d, 2p) was found to be the relatively good choice to compute MKS charges for reproducing the experimental values of molecular dipole moments. Root mean square deviation of computed dipole moments for 21 small polar molecules is about 0.1969 D.
