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
The partial potential energy surface of the I + HI →IH + I reaction involving the translational and vibrational motions has been constructed at the QCISD( T )//MP4SDQ level with the pseudo potential method that i...The partial potential energy surface of the I + HI →IH + I reaction involving the translational and vibrational motions has been constructed at the QCISD( T )//MP4SDQ level with the pseudo potential method that is helpful to interpreting the scattering resonance states. The lifetimes of the scattering resonance states in the title reaction obtained from the partial potential energy surface are about 90-120 fs, which agrees with the result of high-resolved threshold photodetachment spectroscopy of anion IHI^- measured by Neumark.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
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 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
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
The potential energy surface for the electronic ground state of the HXeBr molecule is constructed from more than 4200 ab initio points calculated using the internally contracted multi-reference configuration interacti...The potential energy surface for the electronic ground state of the HXeBr molecule is constructed from more than 4200 ab initio points calculated using the internally contracted multi-reference configuration interaction method with the Davidson correction (icMRCI + Q). The stabilities and dissociation barriers are identified from the potential energy surface. The three-body dissociation channel is found to be the dominant dissociation channel for HXeBr. Low-lying vibrational energy levels of HXeBr calculated using the Lanczos algorithm are found to be in good agreement with the available experimental band origins.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 partial potential energy surface was constructed by ab initio method [QCISD(T)/6- 311++G(2df,2pd)]for F+CH4→HF+CH3 reaction system. It not only explained the reaction mechanism brought forward by Diego Tr...The partial potential energy surface was constructed by ab initio method [QCISD(T)/6- 311++G(2df,2pd)]for F+CH4→HF+CH3 reaction system. It not only explained the reaction mechanism brought forward by Diego Troya by means of quasiclassical trajectory (QCT) but also successfully validated Kopin Liu's experimental phenomena about the existence of the reactive resonance. The lifetime of the scattering resonance state was about 0.07 ps. All these were in agreement with the experiments.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
Satellite altimetry observations,including the upcoming Surface Water and Ocean Topography mission,provide snapshots of the global sea surface high anomaly field.The common practice in analyzing these surface elevatio...Satellite altimetry observations,including the upcoming Surface Water and Ocean Topography mission,provide snapshots of the global sea surface high anomaly field.The common practice in analyzing these surface elevation data is to convert them into surface velocity based on the geostrophic approximation.With increasing horizontal resolution in satellite observations,sea surface elevation data will contain many dynamical signals other than the geostrophic velocity.A new physical quantity,the available surface potential energy,is conceptually introduced in this study defined as the density multiplied by half of the squared deviation from the local mean reference surface elevation.This gravitational potential energy is an intrinsic property of the sea surface height field and it is an important component of ocean circulation energetics,especially near the sea surface.In connection with other energetic terms,this new variable may help us better understand the dynamics of oceanic circulation,in particular the processes in connection with the free surface data collected through satellite altimetry.The preliminary application of this concept to the numerically generated monthly mean Global Ocean Data Assimilation System data and Archiving,Validation,and Interpretation of Satellite Oceanographic altimeter data shows that the available surface potential energy is potentially linked to other dynamic variables,such as the total kinetic energy,eddy kinetic energy and available potential energy.展开更多
In this letter ab initio electronic structure calculations are performed for extensive geometries Of CS2. A newly written program is used to fit the computed energies into the Sorbie-Murrel function, whose contour plo...In this letter ab initio electronic structure calculations are performed for extensive geometries Of CS2. A newly written program is used to fit the computed energies into the Sorbie-Murrel function, whose contour plots are illustrated.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
Lithium has been paid great attention in recent years thanks to its significant appli-cations for battery and lightweight alloy.Developing a potential model with high ac-curacy and efficiency is impor-tant for theoret...Lithium has been paid great attention in recent years thanks to its significant appli-cations for battery and lightweight alloy.Developing a potential model with high ac-curacy and efficiency is impor-tant for theoretical simulation of lithium materials.Here,we build a deep learning potential(DP)for elemental lithium based on a concurrent-learning scheme and DP representation of the density-functional theory(DFT)potential energy surface(PES),the DP model enables material simulations with close-to DFT accuracy but at much lower computational cost.The simulations show that basic parameters,equation of states,elasticity,defects and surface are consistent with the first principles results.More notably,the liquid radial distribution func-tion based on our DP model is found to match well with experiment data.Our results demon-strate that the developed DP model can be used for the simulation of lithium materials.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
The preparation of TiC coating on Ti alloy surface to improve the wear resistance has attracted attention from researchers in aerospace field.The service life of TiC coating is related to the interfacial adhesion prop...The preparation of TiC coating on Ti alloy surface to improve the wear resistance has attracted attention from researchers in aerospace field.The service life of TiC coating is related to the interfacial adhesion properties between TiC coating and Ti alloy substrate.However,it is difficult to explain its interfacial adhesion mechanism by experimental methods.Based on the termination of atoms on the TiC surface,two TiC/Ti interface models named as the C-terminated-TiC(111)/Ti(0001) and Ti-terminated-TiC(11)/Ti(0001) interface were constructed by first-principles.The interfacial electronic characteristic of C-Ti bond is a mixture of polar covalent and metal bonds,and that of Ti-Ti bond is the metal bond.The tensile strains of both C-terminated-TiC(111)/Ti(0001) and Ti-terminated-TiC(111)/Ti(0001) interface in the fracture stage are ranged from 12% to 14%.Their maximum tensile stresses are 16.201 GPa and 15.590GPa,respectively.The sliding potential energy surface maximum of C-terminated-TiC(111)/Ti(0001) and Ti-terminated-TiC(111)/Ti(0001) interface are 5.387 J/m^(2) and 0.271 J/m^(2),respectively.And the sliding potential barriers on the minimum energy path are 2.094 J/m2and 0.136 J/m^(2) with an ideal shear strength of 20.32 GPa and 1.61 GPa,respectively.In summary,the interfacial adhesion property of C-terminated-TiC(111)/Ti(0001) interface is better than that of Ti-terminated-TiC(111)/Ti(0001) interface.展开更多
We calculate the three-dimensional potential energy surface(PES)for the fission of the compound nucleus^(236)U using covariant density functional theory with constraints on the axial quadrupole and octupole deformatio...We calculate the three-dimensional potential energy surface(PES)for the fission of the compound nucleus^(236)U using covariant density functional theory with constraints on the axial quadrupole and octupole deformations(β_(2),β_(3))coexistence of the elongated and compact fission modes is predicted for comes shallow across a large range of quadrupole and octupole deformations for small scission line in the(β_(2),β_(3))plane extends to a shallow band,leading to fluctuations of several to ten MeV in the estimated total kinetic energies and of several to approximately ten nucleons in the fragment masses.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
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
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Supported by the National Natural Science Foundation of China(No. 20173032) Ph. D. Special Research Foundation ofMinistry of Education of China(No. 20020422027).
文摘The partial potential energy surface of the I + HI →IH + I reaction involving the translational and vibrational motions has been constructed at the QCISD( T )//MP4SDQ level with the pseudo potential method that is helpful to interpreting the scattering resonance states. The lifetimes of the scattering resonance states in the title reaction obtained from the partial potential energy surface are about 90-120 fs, which agrees with the result of high-resolved threshold photodetachment spectroscopy of anion IHI^- measured by Neumark.
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 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 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.
文摘The potential energy surface for the electronic ground state of the HXeBr molecule is constructed from more than 4200 ab initio points calculated using the internally contracted multi-reference configuration interaction method with the Davidson correction (icMRCI + Q). The stabilities and dissociation barriers are identified from the potential energy surface. The three-body dissociation channel is found to be the dominant dissociation channel for HXeBr. Low-lying vibrational energy levels of HXeBr calculated using the Lanczos algorithm are found to be in good agreement with the available experimental band origins.
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the support of the Grant from the National Natural Science Foundation of China No.20573064 Ph.D.Special Research Foundation of Chinese Education Department.
文摘The partial potential energy surface was constructed by ab initio method [QCISD(T)/6- 311++G(2df,2pd)]for F+CH4→HF+CH3 reaction system. It not only explained the reaction mechanism brought forward by Diego Troya by means of quasiclassical trajectory (QCT) but also successfully validated Kopin Liu's experimental phenomena about the existence of the reactive resonance. The lifetime of the scattering resonance state was about 0.07 ps. All these were in agreement with the experiments.
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The National Natural Science Foundation of China under contract Nos 92058201 and 41776040the Chinese Academy of Sciences under contract Nos ZDBS-LY-DQC011,XDA15020901 and ISEE2018PY05。
文摘Satellite altimetry observations,including the upcoming Surface Water and Ocean Topography mission,provide snapshots of the global sea surface high anomaly field.The common practice in analyzing these surface elevation data is to convert them into surface velocity based on the geostrophic approximation.With increasing horizontal resolution in satellite observations,sea surface elevation data will contain many dynamical signals other than the geostrophic velocity.A new physical quantity,the available surface potential energy,is conceptually introduced in this study defined as the density multiplied by half of the squared deviation from the local mean reference surface elevation.This gravitational potential energy is an intrinsic property of the sea surface height field and it is an important component of ocean circulation energetics,especially near the sea surface.In connection with other energetic terms,this new variable may help us better understand the dynamics of oceanic circulation,in particular the processes in connection with the free surface data collected through satellite altimetry.The preliminary application of this concept to the numerically generated monthly mean Global Ocean Data Assimilation System data and Archiving,Validation,and Interpretation of Satellite Oceanographic altimeter data shows that the available surface potential energy is potentially linked to other dynamic variables,such as the total kinetic energy,eddy kinetic energy and available potential energy.
文摘In this letter ab initio electronic structure calculations are performed for extensive geometries Of CS2. A newly written program is used to fit the computed energies into the Sorbie-Murrel function, whose contour plots are illustrated.
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supported by the National Natural Science Founda-tion of China(No.22203026,No.22203025,and No.12174080)the National Key R&D Program of China(No.2022YFA1602601)+1 种基金the Fundamental Research Funds for the Central Universities(JZ2022HGTA0313 and JZ2022HGQA0198)the Anhui Provincial Nat-ural Science Foundation(2208085QB44).
文摘Lithium has been paid great attention in recent years thanks to its significant appli-cations for battery and lightweight alloy.Developing a potential model with high ac-curacy and efficiency is impor-tant for theoretical simulation of lithium materials.Here,we build a deep learning potential(DP)for elemental lithium based on a concurrent-learning scheme and DP representation of the density-functional theory(DFT)potential energy surface(PES),the DP model enables material simulations with close-to DFT accuracy but at much lower computational cost.The simulations show that basic parameters,equation of states,elasticity,defects and surface are consistent with the first principles results.More notably,the liquid radial distribution func-tion based on our DP model is found to match well with experiment data.Our results demon-strate that the developed DP model can be used for the simulation of lithium materials.
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This study was co-supported by the National Natural Science Foundation of China(No.51771167)the Natural Science Foundation of Hebei Province,China(No.E2021203191)+2 种基金the Hebei Province Innovation Ability Promotion Project,China(No.22567609H)the Natural Science Foundation of Fujian Province,China(No.2020J05196)the Innovative Funding Project for Doctoral Postgraduates of Hebei Province,China(No.CXZZBS2022147).
文摘The preparation of TiC coating on Ti alloy surface to improve the wear resistance has attracted attention from researchers in aerospace field.The service life of TiC coating is related to the interfacial adhesion properties between TiC coating and Ti alloy substrate.However,it is difficult to explain its interfacial adhesion mechanism by experimental methods.Based on the termination of atoms on the TiC surface,two TiC/Ti interface models named as the C-terminated-TiC(111)/Ti(0001) and Ti-terminated-TiC(11)/Ti(0001) interface were constructed by first-principles.The interfacial electronic characteristic of C-Ti bond is a mixture of polar covalent and metal bonds,and that of Ti-Ti bond is the metal bond.The tensile strains of both C-terminated-TiC(111)/Ti(0001) and Ti-terminated-TiC(111)/Ti(0001) interface in the fracture stage are ranged from 12% to 14%.Their maximum tensile stresses are 16.201 GPa and 15.590GPa,respectively.The sliding potential energy surface maximum of C-terminated-TiC(111)/Ti(0001) and Ti-terminated-TiC(111)/Ti(0001) interface are 5.387 J/m^(2) and 0.271 J/m^(2),respectively.And the sliding potential barriers on the minimum energy path are 2.094 J/m2and 0.136 J/m^(2) with an ideal shear strength of 20.32 GPa and 1.61 GPa,respectively.In summary,the interfacial adhesion property of C-terminated-TiC(111)/Ti(0001) interface is better than that of Ti-terminated-TiC(111)/Ti(0001) interface.
基金Supported by the National Natural Science Foundation of China(11875225,11790325,11790320)the Special Fund from the China Nuclear Data Center+1 种基金the Fundamental Research Funds for the Central Universitiesthe Fok Ying-Tong Education Foundation。
文摘We calculate the three-dimensional potential energy surface(PES)for the fission of the compound nucleus^(236)U using covariant density functional theory with constraints on the axial quadrupole and octupole deformations(β_(2),β_(3))coexistence of the elongated and compact fission modes is predicted for comes shallow across a large range of quadrupole and octupole deformations for small scission line in the(β_(2),β_(3))plane extends to a shallow band,leading to fluctuations of several to ten MeV in the estimated total kinetic energies and of several to approximately ten nucleons in the fragment masses.
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.