In this paper, we deduce the analytical form of many-body interatomic potentials based on the Green's function in tight-binding representation. The many-body potentials are expressed as the functions of the hoppin...In this paper, we deduce the analytical form of many-body interatomic potentials based on the Green's function in tight-binding representation. The many-body potentials are expressed as the functions of the hopping integrals which are the physical origin of cohesion of atoms. For thesimple case of s-valent system, the inversion of the many-body potentials are discussed in detail by using the lattice inversion method.展开更多
By using the B3P86/aug-cc-pvtz method, the accurate equilibrium geometry of the AlSO （Cs, X2AH） molecule has been calculated and compared with available theoreticM values. The obtained results show that the AlSO mol...By using the B3P86/aug-cc-pvtz method, the accurate equilibrium geometry of the AlSO （Cs, X2AH） molecule has been calculated and compared with available theoreticM values. The obtained results show that the AlSO molecule has a most stable structure with bond lengths of ROA1= 0.1864 nm, ROS=0.1623 nm, RAIS=0.2450 nm, together with a dissociation energy of 13.88 eV. The possible electronic states and their reasonable dissociation limits for the ground state of the AlSO molecule were determined based on the principle of atomic and molecular reaction statics. The analytic potential energy function of the AlSO molecule was derived by the many-body expansion theory and the contour lines were constructed for the first time, which show the internal information of the AlSO molecule, including the equilibrium structure and stable point. The analysis demonstrates that the obtained potential energy function of AlSO is reaSonable and successful and the present investigations provide important insights for further study on molecular reaction dynamics.展开更多
In this paper, the energy, equilibrium geometry, and harmonic frequency of the ground electronic state of PO2 are computed using the B3LYP, B3P86, CCSD（T）, and QCISD（T） methods in conjunction with the 6-311＋＋G（...In this paper, the energy, equilibrium geometry, and harmonic frequency of the ground electronic state of PO2 are computed using the B3LYP, B3P86, CCSD（T）, and QCISD（T） methods in conjunction with the 6-311＋＋G（3df, 3pd） and cc-pVTZ basis sets. A comparison between the computational results and the experimental values indicates that the B3P86/6-311＋＋G（3df, 3pd） method can give better energy calculation results for the PO2 molecule. It is shown that the ground state of the PO2 molecule has C2v symmetry and its ground electronic state is X2A1. The equilibrium parameters of the structure are Rp-o = 0.1465 am, ZOPO = 134.96°, and the dissociation energy is Ed = 19.218 eV. The bent vibrational frequency Ul = 386 cm-1, symmetric stretching frequency v2 = 1095 cm-1, and asymmetric stretching frequency ua = 1333 em-1 are obtained. On the basis of atomic and molecular reaction statics, a reasonable dissociation limit for the ground state of the PO2 molecule is determined. Then the analytic potential energy function of the PO2 molecule is derived using many-body expansion theory. The potential curves correctly reproduce the configurations and the dissociation energy for the PO2 molecule.展开更多
In this paper the equilibrium structure of HCO has been optimized by using density functional theory （DFT）/ B3P86 method and CC-PVTZ basis. It has a bent （Cs, X^2A＇） ground state structure with an angle of 124.40...In this paper the equilibrium structure of HCO has been optimized by using density functional theory （DFT）/ B3P86 method and CC-PVTZ basis. It has a bent （Cs, X^2A＇） ground state structure with an angle of 124.4095 °. The vibronic frequencies and force constants have also been calculated. Based on the principles of atomic and molecular reaction statics, the possible electronic states and reasonable dissociation limits for the ground state of HCO molecule have been determined. The analytic potential energy function of HCO （X^2A＇） molecule has been derived by using the many-body expansion theory. The contour lines are constructed, which show the static properties of HCO （X^2A＇）, such as the equilibrium structure, the lowest energies, etc. The potential energy surface of HCO （X^2A＇） is reasonable and very satisfactory.展开更多
We applied an approach to the development of many-body interatomic potentials for NiZr alloys,gaining an improved accuracy and reliability.The functional form of the potential is that of the embedded method,but it has...We applied an approach to the development of many-body interatomic potentials for NiZr alloys,gaining an improved accuracy and reliability.The functional form of the potential is that of the embedded method,but it has been improved as follows. (1) The database used for the development of the potential includes both experimental data and a large set of energies of different structures of the alloys generated by Fab initio calculations. (2) The optimum parametrization of the potential for the given database is obtained by fitting. Using this approach we developed reliable interatomic potentials for Ni and Zr. The potential accurately reproduces basic equilibrium properties of the alloys.展开更多
The equilibrium structure of flue gas SO2 is optimized using the density functional theory （DFT）/B3P86 method and CC-PV5Z basis. The result shows that it has a bent （C2v, X1A1） ground state structure with an angle...The equilibrium structure of flue gas SO2 is optimized using the density functional theory （DFT）/B3P86 method and CC-PV5Z basis. The result shows that it has a bent （C2v, X1A1） ground state structure with an angle of 119.1184°. The vibronic frequencies and the force constants are also calculated. Based on the principles of atomic and molecular reaction statics （AMIIS）, the possible electronic states and reasonable dissociation limits for the ground state of SO2 molecule are determined. The potential functions of SO and 02 are fitted by the modified Murrell-Sorbie＋c6 （M-S＋c6） potential function and the fitted parameters, the force constants and the spectroscopic constants are obtained, which are all close to the experimental values. The analytic potential energy function of the SO2 （X1A1） molecule is derived using the many-body expansion theory. The contour liues are constructed, which show the static properties of SO2 （XIA1）, such as the equilibrium structure, the lowest energies, the most possible reaction channel, etc.展开更多
Using the density functional method B3LYP with relativistic effective core potential （RECP） for Pu atom, the low-lying excited states （^4Σ^＋, ^6Σ^＋, ^8Σ^＋） for three structures of PuOH molecule were optimize...Using the density functional method B3LYP with relativistic effective core potential （RECP） for Pu atom, the low-lying excited states （^4Σ^＋, ^6Σ^＋, ^8Σ^＋） for three structures of PuOH molecule were optimized. The results show that the ground state is X^6Σ^＋ of the linear Pu-O-H （C∞v）, its corresponding equilibrium geometry and dissociation energy are RPu-O = 0.20595 nm, RO-H=0.09581 nm and -8.68 eV, respectively. At the same time, two other metastable structures [PuOH （Cs） and H-Pu-O （C∞v）] were found. The analytical potential energy function has also been derived for whole range using the many-body expansion method. This potential energy function represents the considerable topographical features of PuOH molecule in detail, which is adequately accurate in the whole potential surface and can be used for the molecular reaction dynamics research.展开更多
In this work,we develop a new many-body potential for alpha-hafnium(α-Hf)based on the second moment approximation of tight-binding(TB-SMA)theory by introducing an additional Heaviside step function into the potential...In this work,we develop a new many-body potential for alpha-hafnium(α-Hf)based on the second moment approximation of tight-binding(TB-SMA)theory by introducing an additional Heaviside step function into the potential model and a new analytical scheme of density function.All the parameters of the new potential have been systematically evaluated by fitting to ground-state properties including cohesive energy,lattice constants,elastic constants,vacancy formation energy,structure stability and equation of state.By using the present model,the melting point,melt heat,thermal expansion coefficient,point defects,and low-index surface energies ofα-Hf were calculated through molecular dynamics simulations.Comparing with experiment observations from others,it is shown that these properties can be reproduced reasonably by the present model,some results being more consistent to the experimental data than those by previous suggested models.This indicates that this work is sutiable in TB-SMA potential for hexagonal close packed metals.展开更多
Based on the quantum Sutton-Chen many-body potential,a molecular dynamics simulation was performed to investigate the formation and evolution properties of clusters in liquid Cu with 50 000 atoms.The cluster-type inde...Based on the quantum Sutton-Chen many-body potential,a molecular dynamics simulation was performed to investigate the formation and evolution properties of clusters in liquid Cu with 50 000 atoms.The cluster-type index method(CTIM)was used to describe the complex microstructure transitions.It is demonstrated that the amorphous structures are mainly formed with the three bond-types of 1551,1541 and 1431 in the system,and the icosahedral cluster(12 0 12 0)and other basic polyhedron clusters of(12 2 8 2),(13 1 10 2),(13 3 6 4),(14 1 10 3),(14 2 8 4)and(14 3 6 5)play a critical and leading role in the transition from liquid to glass.The nano-clusters formed in the system consist of some basic clusters and middle cluster configurations by connecting to each other,and distinguish from those obtained by gaseous deposition and ionic spray.From the results of structural parameter pair distribution function g(r),bond-types and basic cluster-types,it is found that the glass transition temperature Tg for liquid metal Cu is about 673 K at the cooling rate of 1.0×1014 K/s.展开更多
The present work is to construct the potential energy function of isotopic molecules. The so-called molecular potential energy function is the electronic energy function under Born-Oppenheimer approximation,in which t...The present work is to construct the potential energy function of isotopic molecules. The so-called molecular potential energy function is the electronic energy function under Born-Oppenheimer approximation,in which the nuclear motions(translational,rotational and vibration motions) are not included,therefore,its nuclear vibration motion and isotopic effect need to be considered. Based on group theory and atomic and molecular reactive statics(AMRS),the reasonable dissociation limits of D2O(1A1)are determined,its equilibrium geometry and dissociation energy are calculated by density-functional theory(DFT) B3lyp,and then,using the many-body expansion method the potential energy function of D2O(1A1) is obtained for the first time. The potential contours are drawn,in which it is found that the reactive channel D + OD→D2O has no threshold energy,so it is a free radical reaction. But the reactive channel O + DD→D2O has a saddle point. The study of collision for D2O(1A1) is under way.展开更多
A photoionization cross section calculation ofMn^＋ is performed in the formalism of many-body perturbation theory for photon energies ranging from 48 eV to 56 eV. We consider excitations from the 3p, 3d, and 4s subsh...A photoionization cross section calculation ofMn^＋ is performed in the formalism of many-body perturbation theory for photon energies ranging from 48 eV to 56 eV. We consider excitations from the 3p, 3d, and 4s subshells. The effects of the strong 3p→ 3d and 3p→ 4s transitions are included as resonant contributions to the total cross sections. Good agreement with experiment is found.展开更多
文摘In this paper, we deduce the analytical form of many-body interatomic potentials based on the Green's function in tight-binding representation. The many-body potentials are expressed as the functions of the hopping integrals which are the physical origin of cohesion of atoms. For thesimple case of s-valent system, the inversion of the many-body potentials are discussed in detail by using the lattice inversion method.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10974139 and 10964002)the Natural Science Foundation of Hainan Province,China(Grant No.110001)+3 种基金Guizhou Province,China(Grant No.[2009]2066)the Scientific Research Foundation by Zhejiang University of Technology,China(Grant No.109003729)the Science-Technology Foundation of Sichuan Province,China(Grant No.09ZQ026-049)the Fund of Aiding Elites' Research Condition of Guizhou Province, China(Grant No.TZJF-2008-42)
文摘By using the B3P86/aug-cc-pvtz method, the accurate equilibrium geometry of the AlSO （Cs, X2AH） molecule has been calculated and compared with available theoreticM values. The obtained results show that the AlSO molecule has a most stable structure with bond lengths of ROA1= 0.1864 nm, ROS=0.1623 nm, RAIS=0.2450 nm, together with a dissociation energy of 13.88 eV. The possible electronic states and their reasonable dissociation limits for the ground state of the AlSO molecule were determined based on the principle of atomic and molecular reaction statics. The analytic potential energy function of the AlSO molecule was derived by the many-body expansion theory and the contour lines were constructed for the first time, which show the internal information of the AlSO molecule, including the equilibrium structure and stable point. The analysis demonstrates that the obtained potential energy function of AlSO is reaSonable and successful and the present investigations provide important insights for further study on molecular reaction dynamics.
基金Project supported by the National Natural Science Foundation of China (Grant No. 11047176)the Research Foundation of Education Bureau of Hubei Province, China (Grant Nos. Q20111305 and B20101303)
文摘In this paper, the energy, equilibrium geometry, and harmonic frequency of the ground electronic state of PO2 are computed using the B3LYP, B3P86, CCSD（T）, and QCISD（T） methods in conjunction with the 6-311＋＋G（3df, 3pd） and cc-pVTZ basis sets. A comparison between the computational results and the experimental values indicates that the B3P86/6-311＋＋G（3df, 3pd） method can give better energy calculation results for the PO2 molecule. It is shown that the ground state of the PO2 molecule has C2v symmetry and its ground electronic state is X2A1. The equilibrium parameters of the structure are Rp-o = 0.1465 am, ZOPO = 134.96°, and the dissociation energy is Ed = 19.218 eV. The bent vibrational frequency Ul = 386 cm-1, symmetric stretching frequency v2 = 1095 cm-1, and asymmetric stretching frequency ua = 1333 em-1 are obtained. On the basis of atomic and molecular reaction statics, a reasonable dissociation limit for the ground state of the PO2 molecule is determined. Then the analytic potential energy function of the PO2 molecule is derived using many-body expansion theory. The potential curves correctly reproduce the configurations and the dissociation energy for the PO2 molecule.
基金Project supported by the National Natural Science Foundation of China and CAEP （Grant No 10676025）, by the scientific project of Jiangxi education departments of China （Grant Nos 2006261 and 2006236）, and by the Research Funds of College of Jinggangshan, China （Grant No JZ0616）.
文摘In this paper the equilibrium structure of HCO has been optimized by using density functional theory （DFT）/ B3P86 method and CC-PVTZ basis. It has a bent （Cs, X^2A＇） ground state structure with an angle of 124.4095 °. The vibronic frequencies and force constants have also been calculated. Based on the principles of atomic and molecular reaction statics, the possible electronic states and reasonable dissociation limits for the ground state of HCO molecule have been determined. The analytic potential energy function of HCO （X^2A＇） molecule has been derived by using the many-body expansion theory. The contour lines are constructed, which show the static properties of HCO （X^2A＇）, such as the equilibrium structure, the lowest energies, etc. The potential energy surface of HCO （X^2A＇） is reasonable and very satisfactory.
基金Supported by the National Natural Science Foundation of China(No.2 9892 16 6 ,2 980 30 0 6 ,2 99830 0 1)
文摘We applied an approach to the development of many-body interatomic potentials for NiZr alloys,gaining an improved accuracy and reliability.The functional form of the potential is that of the embedded method,but it has been improved as follows. (1) The database used for the development of the potential includes both experimental data and a large set of energies of different structures of the alloys generated by Fab initio calculations. (2) The optimum parametrization of the potential for the given database is obtained by fitting. Using this approach we developed reliable interatomic potentials for Ni and Zr. The potential accurately reproduces basic equilibrium properties of the alloys.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11147158 and 10965002)the Natural Science Foundation of Jiangxi Province, China (Grant No. 2010GQW0031)the Scientific Project of Jiangxi Education Department, China (Grant No. GJJ11540)
文摘The equilibrium structure of flue gas SO2 is optimized using the density functional theory （DFT）/B3P86 method and CC-PV5Z basis. The result shows that it has a bent （C2v, X1A1） ground state structure with an angle of 119.1184°. The vibronic frequencies and the force constants are also calculated. Based on the principles of atomic and molecular reaction statics （AMIIS）, the possible electronic states and reasonable dissociation limits for the ground state of SO2 molecule are determined. The potential functions of SO and 02 are fitted by the modified Murrell-Sorbie＋c6 （M-S＋c6） potential function and the fitted parameters, the force constants and the spectroscopic constants are obtained, which are all close to the experimental values. The analytic potential energy function of the SO2 （X1A1） molecule is derived using the many-body expansion theory. The contour liues are constructed, which show the static properties of SO2 （XIA1）, such as the equilibrium structure, the lowest energies, the most possible reaction channel, etc.
文摘Using the density functional method B3LYP with relativistic effective core potential （RECP） for Pu atom, the low-lying excited states （^4Σ^＋, ^6Σ^＋, ^8Σ^＋） for three structures of PuOH molecule were optimized. The results show that the ground state is X^6Σ^＋ of the linear Pu-O-H （C∞v）, its corresponding equilibrium geometry and dissociation energy are RPu-O = 0.20595 nm, RO-H=0.09581 nm and -8.68 eV, respectively. At the same time, two other metastable structures [PuOH （Cs） and H-Pu-O （C∞v）] were found. The analytical potential energy function has also been derived for whole range using the many-body expansion method. This potential energy function represents the considerable topographical features of PuOH molecule in detail, which is adequately accurate in the whole potential surface and can be used for the molecular reaction dynamics research.
基金supported by the National Natural Science Foundation of China(Grant Nos.51071018 and 51271018)
文摘In this work,we develop a new many-body potential for alpha-hafnium(α-Hf)based on the second moment approximation of tight-binding(TB-SMA)theory by introducing an additional Heaviside step function into the potential model and a new analytical scheme of density function.All the parameters of the new potential have been systematically evaluated by fitting to ground-state properties including cohesive energy,lattice constants,elastic constants,vacancy formation energy,structure stability and equation of state.By using the present model,the melting point,melt heat,thermal expansion coefficient,point defects,and low-index surface energies ofα-Hf were calculated through molecular dynamics simulations.Comparing with experiment observations from others,it is shown that these properties can be reproduced reasonably by the present model,some results being more consistent to the experimental data than those by previous suggested models.This indicates that this work is sutiable in TB-SMA potential for hexagonal close packed metals.
基金Projects(5027102650571037)supported by the National Natural Science Foundation of China
文摘Based on the quantum Sutton-Chen many-body potential,a molecular dynamics simulation was performed to investigate the formation and evolution properties of clusters in liquid Cu with 50 000 atoms.The cluster-type index method(CTIM)was used to describe the complex microstructure transitions.It is demonstrated that the amorphous structures are mainly formed with the three bond-types of 1551,1541 and 1431 in the system,and the icosahedral cluster(12 0 12 0)and other basic polyhedron clusters of(12 2 8 2),(13 1 10 2),(13 3 6 4),(14 1 10 3),(14 2 8 4)and(14 3 6 5)play a critical and leading role in the transition from liquid to glass.The nano-clusters formed in the system consist of some basic clusters and middle cluster configurations by connecting to each other,and distinguish from those obtained by gaseous deposition and ionic spray.From the results of structural parameter pair distribution function g(r),bond-types and basic cluster-types,it is found that the glass transition temperature Tg for liquid metal Cu is about 673 K at the cooling rate of 1.0×1014 K/s.
基金Supported by the National Natural Science Foundation of China (Grant No. NSAF10676022)
文摘The present work is to construct the potential energy function of isotopic molecules. The so-called molecular potential energy function is the electronic energy function under Born-Oppenheimer approximation,in which the nuclear motions(translational,rotational and vibration motions) are not included,therefore,its nuclear vibration motion and isotopic effect need to be considered. Based on group theory and atomic and molecular reactive statics(AMRS),the reasonable dissociation limits of D2O(1A1)are determined,its equilibrium geometry and dissociation energy are calculated by density-functional theory(DFT) B3lyp,and then,using the many-body expansion method the potential energy function of D2O(1A1) is obtained for the first time. The potential contours are drawn,in which it is found that the reactive channel D + OD→D2O has no threshold energy,so it is a free radical reaction. But the reactive channel O + DD→D2O has a saddle point. The study of collision for D2O(1A1) is under way.
基金The project supported by the Research Fund for the Doctoral Program of Higher Education under Grant No. 2002610001 and the National Natural Science Foundation of China under Grant No. 60054402
文摘A photoionization cross section calculation ofMn^＋ is performed in the formalism of many-body perturbation theory for photon energies ranging from 48 eV to 56 eV. We consider excitations from the 3p, 3d, and 4s subshells. The effects of the strong 3p→ 3d and 3p→ 4s transitions are included as resonant contributions to the total cross sections. Good agreement with experiment is found.
