Potential energy surfaces(PESs), vibrational frequencies, and infrared spectra are calculated for NF_(3)^(+) using ab initio calculations, based on UCCSD(T)/cc-p VTZ combined with vibrational configuration interaction...Potential energy surfaces(PESs), vibrational frequencies, and infrared spectra are calculated for NF_(3)^(+) using ab initio calculations, based on UCCSD(T)/cc-p VTZ combined with vibrational configuration interaction(VCI). Based on an iterative algorithm, the surfaces(SURF) program adds automatic points to the lattice representation of the potential function, the one-dimensional and two-dimensional PESs are calculated after reaching a convergence threshold, finally the smooth image of the potential energy surface is fitted. The PESs accurately account for the interaction between the different modes, with the mode q_(6) symmetrical stretching vibrations having the greatest effect on the potential energy change of the whole system throughout the potential energy surface shift. The anharmonic frequencies are obtained when the VCI matrix is diagonalized. Fundamental frequencies, overtones, and combination bands of NF_(3)^(+) are calculated, which generate the degenerate phenomenon between their frequencies. Finally, the calculated anharmonic frequency is used to plot the infrared spectra.Modal antisymmetric stretching ν_(5) and symmetric stretching ν_(6) exhibit a phenomenon of large-intensity borrowing. This study can provide data to support the characterization in the laboratory.展开更多
A globally accurate potential energy surface is reported for the electronic ground-state H2O＋. The ab initio energies utilized to map the potential energy surface are calculated at the multireference configuration in...A globally accurate potential energy surface is reported for the electronic ground-state H2O＋. The ab initio energies utilized to map the potential energy surface are calculated at the multireference configuration interaction method employing the aug-cc-pVQZ basis set and the full valence complete active space wave function as reference. In order to improve accu- racy of the resulting raw ab initio energies, they are then extrapolated to the complete basis set limit and most importantly to the full configuration-interaction limit by semiempirically correcting the dynamical correlation using the double many- body expansion-scaled external correlation method. The topographical features of the current potential energy surface were examined in detail, which agree nicely with those of other theoretical work.展开更多
Equilibrium parameters of ozone, such as equilibrium geometry structure parameters, force constants and dissociation energy are presented by CBS-Q ab initio calculations. The calculated equilibrium geometry structure ...Equilibrium parameters of ozone, such as equilibrium geometry structure parameters, force constants and dissociation energy are presented by CBS-Q ab initio calculations. The calculated equilibrium geometry structure parameters and energy are in agreement with the corresponding experimental values. The potential energy function of ozone with a C2v symmetry in the ground state is described by the simplified Sorbie-Murrell many-body expansion potential function according to the ozone molecule symmetry. The contour of bond stretching vibration potential of an O3 in the ground state, with a bond angle （θ） fixed, and the contour of O3 potential for O rotating around O1-O （R1）, with O1-O bond length taken as the one at equilibrium, are plotted. Moreover, the potentials are analysed.展开更多
A globally accurate single-sheeted double many-body expansion potential energy surface is reported for the first excited state of HS_2 by fitting the accurate ab initio energies, which are calculated at the multirefer...A globally accurate single-sheeted double many-body expansion potential energy surface is reported for the first excited state of HS_2 by fitting the accurate ab initio energies, which are calculated at the multireference configuration interaction level with the aug-cc-pVQZ basis set. By using the double many-body expansion-scaled external correlation method,such calculated ab initio energies are then slightly corrected by scaling their dynamical correlation. A grid of 2767 ab initio energies is used in the least-square fitting procedure with the total root-mean square deviation being 1.406 kcal · mol^（-1）.The topographical features of the HS_2（A_2A＇） global potential energy surface are examined in detail. The attributes of the stationary points are presented and compared with the corresponding ab initio results as well as experimental and other theoretical data, showing good agreement. The resulting potential energy surface of HS_2（A_2A＇） can be used as a building block for constructing the global potential energy surfaces of larger S/H molecular systems and recommended for dynamic studies on the title molecular system.展开更多
A global potential energy surface(PES)of the ground state of SiH_(2)^(+) system is built by using neural network method based on 18223 ab initio points.The topographic properties of PES are presented and compared with...A global potential energy surface(PES)of the ground state of SiH_(2)^(+) system is built by using neural network method based on 18223 ab initio points.The topographic properties of PES are presented and compared with previous theoretical and experimental studies.The results indicate that the spectroscopic parameters obtained from the new PES are in good agreement with the experimental data.In order to further verify the validity of the new PES,a test dynamics calculation of the Si^(+)+H_(2)(v_(0)=2,j_(0)=0)→H+SiH^(+)reaction has been carried out by using the time-dependent wave packet method.The integral cross sections and rate constants are computed for the title reaction.The reasonable dynamical behavior indicates that the newly constructed PES is suitable for relevant dynamics investigations.展开更多
A full-dimensional analytical potential energy surface （APES） for the F ＋ CH4 →HF ＋ CH3 reaction is developed based on 7127 ab initio energy points at the unrestricted coupled-cluster with single, double, and per...A full-dimensional analytical potential energy surface （APES） for the F ＋ CH4 →HF ＋ CH3 reaction is developed based on 7127 ab initio energy points at the unrestricted coupled-cluster with single, double, and perturbative triple excitations. The correlation-consistent polarized triple-split valence basis set is used. The APES is represented with a many-body expansion containing 239 parameters determined by the least square fitting method. The two-body terms of the APES are fitted by potential energy curves with multi-reference configuration interaction, which can describe the diatomic molecules （CH, H2, HF, and CF） accurately. It is found that the APES can reproduce the geometry and vibrational frequencies of the saddle point better than those available in the literature. The rate constants based on the present APES support the experimental results of Moore et al. [Int. J. Chem. Kin. 26, 813 （1994）]. The analytical first-order derivation of energy is also provided, making the present APES convenient and efficient for investigating the title reaction with quasiclassical trajectory calculations.展开更多
The product rotational polarizations of reaction Li-SHF→LiF-kH at different collision energies, as well as at the different vibrational states and rotational states, are calculated by using the quasi-classical trajec...The product rotational polarizations of reaction Li-SHF→LiF-kH at different collision energies, as well as at the different vibrational states and rotational states, are calculated by using the quasi-classical trajectory method based on a new potential energy surface constructed by Aguado et al. [J. Chem. Phys. 119（2003） 10088]. We investigate the Mignment and the orientation of the product molecule by calculating the P（θr, φr） distribu- tions describing polar angle distribution, the P（θr） distributions describing the k-j＇ correlation and the P（φr） distributions describing the k-k＇-j＇ correlation. We also explore the dependence of reaction probabilities and cross sections on the rotational and vibrational quantum number of the title reaction. It is concluded that the vibrational state has more important impact on the angular distribution, reaction probability and cross section.展开更多
An interaction potential of the Ne-HC1 van der Waals complex is obtained by utilizing the Huxley analytic potential function to fit the accurate interaction energy data, which have been computed at the coupled cluster...An interaction potential of the Ne-HC1 van der Waals complex is obtained by utilizing the Huxley analytic potential function to fit the accurate interaction energy data, which have been computed at the coupled cluster singles and doubles including connected triple excitations level and with the augmented correlation consistent polarized valence quintuple zeta basis set extended with a set of 3s3p2dlflg mid-bond functions [CCSD （T）/aug-cc-pV5Z-33211]. The close coupling calculation of state-to-state partial cross sections for collision of Ne with HC1 is first performed by employing the fitted interaction potential. This calculation is performed at the incident energies： 40, 60, 75 and 100 meV, separately. The effects of the long-range attractive and the short-range anisotropic interactions on the inelastic state-to-state partial cross sections are discussed in detail. Two maxima are present in the rotationally inelastic partial cross sections and they originate from different mechanisms.展开更多
The potential energy snrface of a CO2-N2 mixture is determined by using an inversion method, together with a new collision integral correlation [J. Phys. Chem. R@ Data 19 1179 （1990）]. With the new invert potential,...The potential energy snrface of a CO2-N2 mixture is determined by using an inversion method, together with a new collision integral correlation [J. Phys. Chem. R@ Data 19 1179 （1990）]. With the new invert potential, the transport properties of CO2-N2 mixture are presented in a temperature range front 273.15 K to 3273.15 K at low density by employing the Chapman-Enskog scheme and the Wang Chang-Uhlenbeck de Boer theory, consisting of a viscosity coefficient, a thermal conductivity coefficient, a binary diffusion coefficient, and a thermal diffusion factor. The accuracy of the predicted results is estimated to be 2% for viscosity, 5% for thermal conductivity, and 10% for binary diffusion coefficient.展开更多
Combining first-principles accuracy and empirical-potential efficiency for the description of the potential energy surface(PES)is the philosopher's stone for unraveling the nature of matter via atomistic simulatio...Combining first-principles accuracy and empirical-potential efficiency for the description of the potential energy surface(PES)is the philosopher's stone for unraveling the nature of matter via atomistic simulation.This has been particularly challenging for multi-component alloy systems due to the complex and non-linear nature of the associated PES.In this work,we develop an accurate PES model for the Al-Cu-Mg system by employing deep potential(DP),a neural network based representation of the PES,and DP generator(DP-GEN),a concurrent-learning scheme that generates a compact set of ab initio data for training.The resulting DP model gives predictions consistent with first-principles calculations for various binary and ternary systems on their fundamental energetic and mechanical properties,including formation energy,equilibrium volume,equation of state,interstitial energy,vacancy and surface formation energy,as well as elastic moduli.Extensive benchmark shows that the DP model is ready and will be useful for atomistic modeling of the Al-Cu-Mg system within the full range of concentration.展开更多
Kinetic investigations including quasi-classical trajectory and canonical unified statistical theory method calculations are carried out on a potential energy surface for the hydrogen-abstraction reaction from methane...Kinetic investigations including quasi-classical trajectory and canonical unified statistical theory method calculations are carried out on a potential energy surface for the hydrogen-abstraction reaction from methane by atom O(^3P).The surface is constructed using a modified Shepard interpolation method.The ab initio calculations are performed at the CCSD(T)level.Taking account of the contribution of inner core electrons to electronic correlation interaction in ab initio electronic structure calculations,modified optimized aug-cc-pCVQZ basis sets are applied to the all-electrons calculations.On this potential energy surface,the triplet oxygen atom attacks methane in a near-collinear H-CH3 direction to form a saddle point with barrier height of 13.55 kcal/mol,which plays a key role in the kinetics of the title reaction.For the temperature range of 298-2500 K,our calculated thermal rate constants for the O(^3P)+CH4→OH+CH3 reaction show good agreement with relevant experimental data.This work provides detailed mechanism of this gas-phase reaction and a theoretical guidance for methane combustion.展开更多
The stereodynamical properties of H（^2S） ＋ NH（v = 0,j = 0,2,5,10）→N（^4S） ＋ H2 reactions are studied in this paper by using the quasi-classical trajectory（QCT） method with different collision energies on the...The stereodynamical properties of H（^2S） ＋ NH（v = 0,j = 0,2,5,10）→N（^4S） ＋ H2 reactions are studied in this paper by using the quasi-classical trajectory（QCT） method with different collision energies on the double many-body expansion（DMBE） potential energy surface（PES）（Poveda L A and Varandas A J C 2005 Phys.Chem.Chem.Phys.7 2867）.In a range of collision energy from 2 to 20 kcal/mol,the vibrational rotational quantum numbers of the NH molecules are specifically investigated on v = 0 and j = 0,2,5,10 respectively.The distributions of P（θr）,P（φr）,P（θr,φr）,（2π/σ）（dσ（00）/dωt）differential cross-section（DCSs） and integral cross-sections（ICSs） are calculated.The ICSs,computed for collision energies from 2 kcal/mol to 20 kcal/mol,for the ground state are in good agreement with the cited data.The results show that the reagent rotational quantum number and initial collision energy both have a significant effect on the distributions of the k-j＇,the k-k＇-j＇,and the k-k＇ correlations.In addition,the DCS is found to be susceptible to collision energy,but it is not significantly affected by the rotational excitation of reagent.展开更多
Using the Skyrme density functional theory,potential energy surfaces of^(240)Pu with constraints on the axial quadrupole and octupole deformations(q_(20)and q_(30))were calculated.The volume-like and surface-like pair...Using the Skyrme density functional theory,potential energy surfaces of^(240)Pu with constraints on the axial quadrupole and octupole deformations(q_(20)and q_(30))were calculated.The volume-like and surface-like pairing forces,as well as a combination of these two forces,were used for the Hartree–Fock–Bogoliubov approximation.Variations in the least-energy fission path,fission barrier,pairing energy,total kinetic energy,scission line,and mass distribution of the fission fragments based on the different forms of the pairing forces were analyzed and discussed.The fission dynamics were studied based on the timedependent generator coordinate method plus the Gaussian overlap approximation.The results demonstrated a sensitivity of the mass and charge distributions of the fission fragments on the form of the pairing force.Based on the investigation of the neutron-induced fission of^(239)Pu,among the volume,mixed,and surface pairing forces,the mixed pairing force presented a good reproduction of the experimental data.展开更多
Based on the density functional theory, we investigate negatively charged clusters PtlAum^-（l ＋ m = 4）, which show significant catalytic properties in the simultaneous removal of N2O and CO. We find that in these c...Based on the density functional theory, we investigate negatively charged clusters PtlAum^-（l ＋ m = 4）, which show significant catalytic properties in the simultaneous removal of N2O and CO. We find that in these clusters, the platinum atom acts as the adsorption center for N2O, the gold and Pt atoms act as electron donors during the reaction, and the charge transfers from the bimetallic cluster to the N2O molecule. As the proportion of Au in the cluster increases, the d band center shifts down further away from the Fermi level, meanwhile more charge is transferred to the N2O molecule, resulting in weaker N–O bond strength. Therefore bimetallic cluster PtAu3^- shows better catalytic properties than the other clusters,especially pure Pt4^- and Au4^-clusters. This means that there is a synergetic effect between the Pt and Au atoms in the negatively charged bimetallic clusters. Our results help to reveal the mechanism of PtlAum^- bimetallic clusters as excellent catalysts.展开更多
A new ab initio potential energy surface of the Ne-CO complex is developed using single and double excitation coupled-cluster theory with noniterative treatment of triple excitations [CCSD（T）]. The potential has a m...A new ab initio potential energy surface of the Ne-CO complex is developed using single and double excitation coupled-cluster theory with noniterative treatment of triple excitations [CCSD（T）]. The potential has a minimum value of -49.396 cm-1 at Re = 6.40α0 with approximately T-shaped geometry （θe=82.5°）. Bound state energies are calculated up to J = 12. The theoretically predicted transition frequencies and spectroscopic constants are in good agreement with the available experimental results.展开更多
Among many kinds of ways to study the properties of atom and molecule collision, the quasi-classical trajectory （QCT） method is an effective one to investigate the molecular reaction dynamics. QCT calculations have ...Among many kinds of ways to study the properties of atom and molecule collision, the quasi-classical trajectory （QCT） method is an effective one to investigate the molecular reaction dynamics. QCT calculations have been carried out to investigate the stereodynamics of the reactions F ＋ H2/HD/HT→FH ＋ H/D/T, which proceed on the lowest-lying electronic states of the FH2 system based on the potential energy surface （PES） of the 1^ 2A＇ FH2 ground state. Although the QCT method cannot describe all quantum effects in the process of the reaction, it has unique advantages when facing a three-atoms system or complicated polyatomic systems. Differential cross sections （DCSs） and three angle distribution functions P（Or）, P（Фr）, P（Or, Фr） on the PES at the collision of 2.74 kcal/mol have been investigated. The isotope effect becomes more obvious with the reagent molecule H2 turning into HD and HT. P（θr, （Фr）, as the joint probability density function of both polar angles θr and Фr, can reflect the properties of three-dimensional dynamic more intuitively.展开更多
The effects of isotopic variants on stereodynamic properties for the title reactions have been investigated using a quasi-classical trajectory method based on the first excited state NH2（I^2A＇） potential energy sur...The effects of isotopic variants on stereodynamic properties for the title reactions have been investigated using a quasi-classical trajectory method based on the first excited state NH2（I^2A＇） potential energy surface [Li Y Q and Varandas A J C 2010 J. Phys. Chem. A 114 9644]. The forward–backward symmetry scattering of the differential cross section can be observed, which demonstrates that all these reactions follow the insertion mechanism. Three angle distribution functions P（θr）, P（φr）, and P（θr, φr） with different collision energies and target molecules H2/D2/T2 are calculated. It is shown that the product rotational angular momentum is not only aligned, but also oriented along the direction perpendicular to the scattering plane. The title reaction is mainly governed by the ＂in-plane＂ mechanism through the calculated distribution function P（θr, φr）. The observable influences on the rotational polarization of the product by the isotopic substitution of H/D/T can be demonstrated.展开更多
The interaction potential of a He-BH complex is investigated by the coupled-cluster single-double plus perturbative triples （CCSD （T）） method and an augmented correlation consistent polarized valence （aug-cc-pV）...The interaction potential of a He-BH complex is investigated by the coupled-cluster single-double plus perturbative triples （CCSD （T）） method and an augmented correlation consistent polarized valence （aug-cc-pV）5Z basis set extended with a set of （3s3p2dlflg） midbond functions. Using the five two-dimensional model potentials, the first three-dimensional interaction potential energy surface is constructed by interpolating along （r-re） by using a fourth-order polynomial. The cross sections for the rovibrational relaxation of BH in cold and ultracold collisions with 3He atom are calculated based on the three-dimensional potential. The results show that the △v =-1 transition is more efficient than the △v=-2 transition, and that the process of relaxation takes place mainly between rotational energy levels with the same vibration state and the △j=-1 transition is the most efficient. The zero temperature quenching rate coefficient is finite as predicted by Wigner＇s law. The resonance is found to take place around 0.1-1 cm^-1 translational energy, which gives rise to a step in the rate coefficients for temperatures around 0.1-1 K. The final rotational distributions in the state v = 0 resulting from the quenching of state （v = 1,j = 0） at three energies corresponding to the three different regimes are also given.展开更多
A new London-Eyring-Polanyi-Sato potential energy surface is employed in this work to study the stereo properties of the O （^3p） ＋ CH4 → H ＋ OCH3 reaction in its rovibrationally ground state using the quasiclass...A new London-Eyring-Polanyi-Sato potential energy surface is employed in this work to study the stereo properties of the O （^3p） ＋ CH4 → H ＋ OCH3 reaction in its rovibrationally ground state using the quasiclassical trajectory method （QCT）. Our calculations are performed at a range of collision energies, Ec = 1.5 eV^-3.5 eV, and the excitation function obtained by the QCT method accords well with the experimental data. The product rotational polarization is calculated, and the product shows a strong rotational polarization in the centre-of-mass coordinate system. The orientation of the product rotational angular momenta is sensitive to the increase in collision energy, and the alignment of the product rotational angular momenta shows some of the properties of the heavy heavy-light mass combination reactions. In the isotopic substituted reaction study, when the H atoms in methane are replaced by D atoms, the rotational polarization is obviously reduced. The polarization-dependent differential cross section is also studied by this QCT calculation to provide detailed information about the rotational alignment and orientation of the product.展开更多
Based on an extended London-Eyring-Polanyi-Sato （LEPS） potential energy surface （PES）, the Ba q-HF reaction has been studied by the quasi-classical trajectory （QCT） method. The reaction integral cross section as...Based on an extended London-Eyring-Polanyi-Sato （LEPS） potential energy surface （PES）, the Ba q-HF reaction has been studied by the quasi-classical trajectory （QCT） method. The reaction integral cross section as a function of collision energy for the Ba q- HF --＊ BaF q- H reaction is presented and the influence of isotope substitution on the differential cross sections （DCSs） and alignments of the product＇s rotational angular momentum have also been studied. The results suggest that the integral cross sections increase with increasing collision energy, and the vibrational excitation of the reagent has great influence on the DCS. In addition, the product＇s rotational polarization is very strong as a result of heavy-heavy-light （HHL） mass combination, and the distinct effect of isotope substitution on the stereodynamics is also revealed.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.52002318 and 22103061)。
文摘Potential energy surfaces(PESs), vibrational frequencies, and infrared spectra are calculated for NF_(3)^(+) using ab initio calculations, based on UCCSD(T)/cc-p VTZ combined with vibrational configuration interaction(VCI). Based on an iterative algorithm, the surfaces(SURF) program adds automatic points to the lattice representation of the potential function, the one-dimensional and two-dimensional PESs are calculated after reaching a convergence threshold, finally the smooth image of the potential energy surface is fitted. The PESs accurately account for the interaction between the different modes, with the mode q_(6) symmetrical stretching vibrations having the greatest effect on the potential energy change of the whole system throughout the potential energy surface shift. The anharmonic frequencies are obtained when the VCI matrix is diagonalized. Fundamental frequencies, overtones, and combination bands of NF_(3)^(+) are calculated, which generate the degenerate phenomenon between their frequencies. Finally, the calculated anharmonic frequency is used to plot the infrared spectra.Modal antisymmetric stretching ν_(5) and symmetric stretching ν_(6) exhibit a phenomenon of large-intensity borrowing. This study can provide data to support the characterization in the laboratory.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11304185 and 11074151)China Postdoctoral Science Foundation(Grant No.2014M561957)+1 种基金the Postdoctoral Innovation Project of Shandong Province,China(Grant No.201402013)the Shandong Provincial Natural Science Foundation,China(Grant No.ZR2014AM022)
文摘A globally accurate potential energy surface is reported for the electronic ground-state H2O＋. The ab initio energies utilized to map the potential energy surface are calculated at the multireference configuration interaction method employing the aug-cc-pVQZ basis set and the full valence complete active space wave function as reference. In order to improve accu- racy of the resulting raw ab initio energies, they are then extrapolated to the complete basis set limit and most importantly to the full configuration-interaction limit by semiempirically correcting the dynamical correlation using the double many- body expansion-scaled external correlation method. The topographical features of the current potential energy surface were examined in detail, which agree nicely with those of other theoretical work.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10376021 and 10676025）, and the Scientific Research Fund of Sichuan Provincial Education Department, China （Grant No 2006A131）.
文摘Equilibrium parameters of ozone, such as equilibrium geometry structure parameters, force constants and dissociation energy are presented by CBS-Q ab initio calculations. The calculated equilibrium geometry structure parameters and energy are in agreement with the corresponding experimental values. The potential energy function of ozone with a C2v symmetry in the ground state is described by the simplified Sorbie-Murrell many-body expansion potential function according to the ozone molecule symmetry. The contour of bond stretching vibration potential of an O3 in the ground state, with a bond angle （θ） fixed, and the contour of O3 potential for O rotating around O1-O （R1）, with O1-O bond length taken as the one at equilibrium, are plotted. Moreover, the potentials are analysed.
基金Project supported by the National Natural Science Foundation of China(Grant No.11304185)the Taishan Scholar Project of Shandong Province,China+3 种基金the Shandong Provincial Natural Science Foundation,China(Grant No.ZR2014AM022)the Shandong Province Higher Educational Science and Technology Program,China(Grant No.J15LJ03)the China Postdoctoral Science Foundation(Grant No.2014M561957)the Post-doctoral Innovation Project of Shandong Province,China(Grant No.201402013)
文摘A globally accurate single-sheeted double many-body expansion potential energy surface is reported for the first excited state of HS_2 by fitting the accurate ab initio energies, which are calculated at the multireference configuration interaction level with the aug-cc-pVQZ basis set. By using the double many-body expansion-scaled external correlation method,such calculated ab initio energies are then slightly corrected by scaling their dynamical correlation. A grid of 2767 ab initio energies is used in the least-square fitting procedure with the total root-mean square deviation being 1.406 kcal · mol^（-1）.The topographical features of the HS_2（A_2A＇） global potential energy surface are examined in detail. The attributes of the stationary points are presented and compared with the corresponding ab initio results as well as experimental and other theoretical data, showing good agreement. The resulting potential energy surface of HS_2（A_2A＇） can be used as a building block for constructing the global potential energy surfaces of larger S/H molecular systems and recommended for dynamic studies on the title molecular system.
基金supported by Key Projects of Science and Technology in the 13th Five Year Plan of Jilin Provincial Department of Education,China(Grant No.JJKH20200482KJ)。
文摘A global potential energy surface(PES)of the ground state of SiH_(2)^(+) system is built by using neural network method based on 18223 ab initio points.The topographic properties of PES are presented and compared with previous theoretical and experimental studies.The results indicate that the spectroscopic parameters obtained from the new PES are in good agreement with the experimental data.In order to further verify the validity of the new PES,a test dynamics calculation of the Si^(+)+H_(2)(v_(0)=2,j_(0)=0)→H+SiH^(+)reaction has been carried out by using the time-dependent wave packet method.The integral cross sections and rate constants are computed for the title reaction.The reasonable dynamical behavior indicates that the newly constructed PES is suitable for relevant dynamics investigations.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11174117 and 10974078)
文摘A full-dimensional analytical potential energy surface （APES） for the F ＋ CH4 →HF ＋ CH3 reaction is developed based on 7127 ab initio energy points at the unrestricted coupled-cluster with single, double, and perturbative triple excitations. The correlation-consistent polarized triple-split valence basis set is used. The APES is represented with a many-body expansion containing 239 parameters determined by the least square fitting method. The two-body terms of the APES are fitted by potential energy curves with multi-reference configuration interaction, which can describe the diatomic molecules （CH, H2, HF, and CF） accurately. It is found that the APES can reproduce the geometry and vibrational frequencies of the saddle point better than those available in the literature. The rate constants based on the present APES support the experimental results of Moore et al. [Int. J. Chem. Kin. 26, 813 （1994）]. The analytical first-order derivation of energy is also provided, making the present APES convenient and efficient for investigating the title reaction with quasiclassical trajectory calculations.
基金Supported by the National Natural Science Foundation of China under Grants No 11274205
文摘The product rotational polarizations of reaction Li-SHF→LiF-kH at different collision energies, as well as at the different vibrational states and rotational states, are calculated by using the quasi-classical trajectory method based on a new potential energy surface constructed by Aguado et al. [J. Chem. Phys. 119（2003） 10088]. We investigate the Mignment and the orientation of the product molecule by calculating the P（θr, φr） distribu- tions describing polar angle distribution, the P（θr） distributions describing the k-j＇ correlation and the P（φr） distributions describing the k-k＇-j＇ correlation. We also explore the dependence of reaction probabilities and cross sections on the rotational and vibrational quantum number of the title reaction. It is concluded that the vibrational state has more important impact on the angular distribution, reaction probability and cross section.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10676025 and 10574096）, the Discipline Foundation of Anqing Teachers College of China （Grant No 044-k06016000007） and the Anhui Provincial Natural Science Foundation of China （Grant No 20050610010）.
文摘An interaction potential of the Ne-HC1 van der Waals complex is obtained by utilizing the Huxley analytic potential function to fit the accurate interaction energy data, which have been computed at the coupled cluster singles and doubles including connected triple excitations level and with the augmented correlation consistent polarized valence quintuple zeta basis set extended with a set of 3s3p2dlflg mid-bond functions [CCSD （T）/aug-cc-pV5Z-33211]. The close coupling calculation of state-to-state partial cross sections for collision of Ne with HC1 is first performed by employing the fitted interaction potential. This calculation is performed at the incident energies： 40, 60, 75 and 100 meV, separately. The effects of the long-range attractive and the short-range anisotropic interactions on the inelastic state-to-state partial cross sections are discussed in detail. Two maxima are present in the rotationally inelastic partial cross sections and they originate from different mechanisms.
基金supported by the National Natural Science Foundation of China (Grant No. 51006083)the China Postdoctoral Science Foundation (Grant No. 20110491658)the Fundamental Research Funds for the Central Universities
文摘The potential energy snrface of a CO2-N2 mixture is determined by using an inversion method, together with a new collision integral correlation [J. Phys. Chem. R@ Data 19 1179 （1990）]. With the new invert potential, the transport properties of CO2-N2 mixture are presented in a temperature range front 273.15 K to 3273.15 K at low density by employing the Chapman-Enskog scheme and the Wang Chang-Uhlenbeck de Boer theory, consisting of a viscosity coefficient, a thermal conductivity coefficient, a binary diffusion coefficient, and a thermal diffusion factor. The accuracy of the predicted results is estimated to be 2% for viscosity, 5% for thermal conductivity, and 10% for binary diffusion coefficient.
基金the National Natural Science Foundation of China(Grant No.11871110)the National Key Research and Development Program of China(Grant Nos.2016YFB0201200 and 2016YFB0201203)Beijing Academy of Artificial Intelligence(BAAI).
文摘Combining first-principles accuracy and empirical-potential efficiency for the description of the potential energy surface(PES)is the philosopher's stone for unraveling the nature of matter via atomistic simulation.This has been particularly challenging for multi-component alloy systems due to the complex and non-linear nature of the associated PES.In this work,we develop an accurate PES model for the Al-Cu-Mg system by employing deep potential(DP),a neural network based representation of the PES,and DP generator(DP-GEN),a concurrent-learning scheme that generates a compact set of ab initio data for training.The resulting DP model gives predictions consistent with first-principles calculations for various binary and ternary systems on their fundamental energetic and mechanical properties,including formation energy,equilibrium volume,equation of state,interstitial energy,vacancy and surface formation energy,as well as elastic moduli.Extensive benchmark shows that the DP model is ready and will be useful for atomistic modeling of the Al-Cu-Mg system within the full range of concentration.
基金Project supported by the National Natural Science Foundation of China(Grant No.51574016)and completed while the author was in residence at UNSW,Australia supported by the International Cooperation Training Program for Innovative Talents of USTB.
文摘Kinetic investigations including quasi-classical trajectory and canonical unified statistical theory method calculations are carried out on a potential energy surface for the hydrogen-abstraction reaction from methane by atom O(^3P).The surface is constructed using a modified Shepard interpolation method.The ab initio calculations are performed at the CCSD(T)level.Taking account of the contribution of inner core electrons to electronic correlation interaction in ab initio electronic structure calculations,modified optimized aug-cc-pCVQZ basis sets are applied to the all-electrons calculations.On this potential energy surface,the triplet oxygen atom attacks methane in a near-collinear H-CH3 direction to form a saddle point with barrier height of 13.55 kcal/mol,which plays a key role in the kinetics of the title reaction.For the temperature range of 298-2500 K,our calculated thermal rate constants for the O(^3P)+CH4→OH+CH3 reaction show good agreement with relevant experimental data.This work provides detailed mechanism of this gas-phase reaction and a theoretical guidance for methane combustion.
基金supported by the Natural Science Foundation of Shandong Province,China(Grant No.2016ZRB01066)the University Student’s Science and Technology Innovation Fund of Ludong University,China(Grant No.131007)
文摘The stereodynamical properties of H（^2S） ＋ NH（v = 0,j = 0,2,5,10）→N（^4S） ＋ H2 reactions are studied in this paper by using the quasi-classical trajectory（QCT） method with different collision energies on the double many-body expansion（DMBE） potential energy surface（PES）（Poveda L A and Varandas A J C 2005 Phys.Chem.Chem.Phys.7 2867）.In a range of collision energy from 2 to 20 kcal/mol,the vibrational rotational quantum numbers of the NH molecules are specifically investigated on v = 0 and j = 0,2,5,10 respectively.The distributions of P（θr）,P（φr）,P（θr,φr）,（2π/σ）（dσ（00）/dωt）differential cross-section（DCSs） and integral cross-sections（ICSs） are calculated.The ICSs,computed for collision energies from 2 kcal/mol to 20 kcal/mol,for the ground state are in good agreement with the cited data.The results show that the reagent rotational quantum number and initial collision energy both have a significant effect on the distributions of the k-j＇,the k-k＇-j＇,and the k-k＇ correlations.In addition,the DCS is found to be susceptible to collision energy,but it is not significantly affected by the rotational excitation of reagent.
基金supported by the National Key R&D Program of China(No.2022YFA1602000)National Natural Science Foundation of China(Nos.12275081,U2067205,11790325,and U1732138)the Continuous-support Basic Scientific Research Project。
文摘Using the Skyrme density functional theory,potential energy surfaces of^(240)Pu with constraints on the axial quadrupole and octupole deformations(q_(20)and q_(30))were calculated.The volume-like and surface-like pairing forces,as well as a combination of these two forces,were used for the Hartree–Fock–Bogoliubov approximation.Variations in the least-energy fission path,fission barrier,pairing energy,total kinetic energy,scission line,and mass distribution of the fission fragments based on the different forms of the pairing forces were analyzed and discussed.The fission dynamics were studied based on the timedependent generator coordinate method plus the Gaussian overlap approximation.The results demonstrated a sensitivity of the mass and charge distributions of the fission fragments on the form of the pairing force.Based on the investigation of the neutron-induced fission of^(239)Pu,among the volume,mixed,and surface pairing forces,the mixed pairing force presented a good reproduction of the experimental data.
基金Project supported by the National Natural Science Foundation of China(Grants Nos.10804058,11174164,and 11275100)the Science Foundation of Zhejiang Province,China(Grant No.Y607546)the K.C. Wong Magna Foundation in Ningbo University,China
文摘Based on the density functional theory, we investigate negatively charged clusters PtlAum^-（l ＋ m = 4）, which show significant catalytic properties in the simultaneous removal of N2O and CO. We find that in these clusters, the platinum atom acts as the adsorption center for N2O, the gold and Pt atoms act as electron donors during the reaction, and the charge transfers from the bimetallic cluster to the N2O molecule. As the proportion of Au in the cluster increases, the d band center shifts down further away from the Fermi level, meanwhile more charge is transferred to the N2O molecule, resulting in weaker N–O bond strength. Therefore bimetallic cluster PtAu3^- shows better catalytic properties than the other clusters,especially pure Pt4^- and Au4^-clusters. This means that there is a synergetic effect between the Pt and Au atoms in the negatively charged bimetallic clusters. Our results help to reveal the mechanism of PtlAum^- bimetallic clusters as excellent catalysts.
文摘A new ab initio potential energy surface of the Ne-CO complex is developed using single and double excitation coupled-cluster theory with noniterative treatment of triple excitations [CCSD（T）]. The potential has a minimum value of -49.396 cm-1 at Re = 6.40α0 with approximately T-shaped geometry （θe=82.5°）. Bound state energies are calculated up to J = 12. The theoretically predicted transition frequencies and spectroscopic constants are in good agreement with the available experimental results.
基金supported by the National Natural Science Foundation of China(Grant No.11474141)the Scientific Research Foundation for the Returned Overseas Chinese Scholars(Grant No.2014-1685)+2 种基金the Scientific Research Foundation for the Doctor of Liaoning Universitythe Special Fund Based Research New Technology of Methanol Conversion and Coal Instead of Oilthe China Postdoctoral Science Foundation(Grant No.2014M550158)
文摘Among many kinds of ways to study the properties of atom and molecule collision, the quasi-classical trajectory （QCT） method is an effective one to investigate the molecular reaction dynamics. QCT calculations have been carried out to investigate the stereodynamics of the reactions F ＋ H2/HD/HT→FH ＋ H/D/T, which proceed on the lowest-lying electronic states of the FH2 system based on the potential energy surface （PES） of the 1^ 2A＇ FH2 ground state. Although the QCT method cannot describe all quantum effects in the process of the reaction, it has unique advantages when facing a three-atoms system or complicated polyatomic systems. Differential cross sections （DCSs） and three angle distribution functions P（Or）, P（Фr）, P（Or, Фr） on the PES at the collision of 2.74 kcal/mol have been investigated. The isotope effect becomes more obvious with the reagent molecule H2 turning into HD and HT. P（θr, （Фr）, as the joint probability density function of both polar angles θr and Фr, can reflect the properties of three-dimensional dynamic more intuitively.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11474141 and 11274149)the Program of Shenyang Key Laboratory of Optoelectronic Materials and Technology,China(Grant No.F12-254-1-00)+3 种基金the Scientific Research Foundation for Doctors of Liaoning Universitythe Special Fund Based Research New Technology of Methanol Conversion and Coal Instead of Oilthe China Postdoctoral Science Foundation(Grant No.2014M550158)the Program for Liaoning Excellent Talents in University(Grant No.LJQ2014001)
文摘The effects of isotopic variants on stereodynamic properties for the title reactions have been investigated using a quasi-classical trajectory method based on the first excited state NH2（I^2A＇） potential energy surface [Li Y Q and Varandas A J C 2010 J. Phys. Chem. A 114 9644]. The forward–backward symmetry scattering of the differential cross section can be observed, which demonstrates that all these reactions follow the insertion mechanism. Three angle distribution functions P（θr）, P（φr）, and P（θr, φr） with different collision energies and target molecules H2/D2/T2 are calculated. It is shown that the product rotational angular momentum is not only aligned, but also oriented along the direction perpendicular to the scattering plane. The title reaction is mainly governed by the ＂in-plane＂ mechanism through the calculated distribution function P（θr, φr）. The observable influences on the rotational polarization of the product by the isotopic substitution of H/D/T can be demonstrated.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10874001)the Key Grant Project of the Chinese Ministry of Education (Grant No. 208057)the Natural Science Foundation of Anhui Province, China (Grant No. 070416236)
文摘The interaction potential of a He-BH complex is investigated by the coupled-cluster single-double plus perturbative triples （CCSD （T）） method and an augmented correlation consistent polarized valence （aug-cc-pV）5Z basis set extended with a set of （3s3p2dlflg） midbond functions. Using the five two-dimensional model potentials, the first three-dimensional interaction potential energy surface is constructed by interpolating along （r-re） by using a fourth-order polynomial. The cross sections for the rovibrational relaxation of BH in cold and ultracold collisions with 3He atom are calculated based on the three-dimensional potential. The results show that the △v =-1 transition is more efficient than the △v=-2 transition, and that the process of relaxation takes place mainly between rotational energy levels with the same vibration state and the △j=-1 transition is the most efficient. The zero temperature quenching rate coefficient is finite as predicted by Wigner＇s law. The resonance is found to take place around 0.1-1 cm^-1 translational energy, which gives rise to a step in the rate coefficients for temperatures around 0.1-1 K. The final rotational distributions in the state v = 0 resulting from the quenching of state （v = 1,j = 0） at three energies corresponding to the three different regimes are also given.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10604012 and 10974023)the Program for Liaoning Excellent Talentsin University,China (Grant No. LJQ2012002)
文摘A new London-Eyring-Polanyi-Sato potential energy surface is employed in this work to study the stereo properties of the O （^3p） ＋ CH4 → H ＋ OCH3 reaction in its rovibrationally ground state using the quasiclassical trajectory method （QCT）. Our calculations are performed at a range of collision energies, Ec = 1.5 eV^-3.5 eV, and the excitation function obtained by the QCT method accords well with the experimental data. The product rotational polarization is calculated, and the product shows a strong rotational polarization in the centre-of-mass coordinate system. The orientation of the product rotational angular momenta is sensitive to the increase in collision energy, and the alignment of the product rotational angular momenta shows some of the properties of the heavy heavy-light mass combination reactions. In the isotopic substituted reaction study, when the H atoms in methane are replaced by D atoms, the rotational polarization is obviously reduced. The polarization-dependent differential cross section is also studied by this QCT calculation to provide detailed information about the rotational alignment and orientation of the product.
文摘Based on an extended London-Eyring-Polanyi-Sato （LEPS） potential energy surface （PES）, the Ba q-HF reaction has been studied by the quasi-classical trajectory （QCT） method. The reaction integral cross section as a function of collision energy for the Ba q- HF --＊ BaF q- H reaction is presented and the influence of isotope substitution on the differential cross sections （DCSs） and alignments of the product＇s rotational angular momentum have also been studied. The results suggest that the integral cross sections increase with increasing collision energy, and the vibrational excitation of the reagent has great influence on the DCS. In addition, the product＇s rotational polarization is very strong as a result of heavy-heavy-light （HHL） mass combination, and the distinct effect of isotope substitution on the stereodynamics is also revealed.
