基态TiH2分子的结构与分析势能函数

用密度泛函理论的B3lyp方法,Ti原子采用相对论有效实势(LanL2DZ)收缩价基函数,氢原子采用6-311 g**全电子基函数,对TiH2体系的结构进行优化计算.得到TiH2分子最稳态为C2v构型,电子状态为(C2v(X)3A2),平衡核间距,RTi-H=0.1789 nm,键角∠HTiH =123.365°,离解能:De=5.54216 eV.基态简正振动频υ(A1)=485.4150 cm-1,υ(B2)=1507.6533 cm-1,υ(A1)=1580.2361 cm-1.由微观过程的可逆性原理分析了分子的可能离解极限,并用多体项展式理论方法分别导出基态TiH2分子的势能函数,其等值势能面图准确地再现了TiH2分子的结构特征和离解能.由此讨论了TiH2分子反应的势能面静态特征.     

BH2和AlH2分子的结构及其解析势能函数

运用二次组态相关(QCISD)方法，分别选用6-311++G(3df,3pd)和D95(3df,3pd)基组，对BH₂和AlH₂分子的结构进行了优化计算，得到BH₂分子的稳态结构为C_2v构型，电子态为²A₁、平衡核间距R_BH=0.1187nm、键角∠HBH=128.791°、离解能D_e=3.65eV、基态振动频率ν₁(a₁)=1020.103cm^-1,ν₂(a₁)=2598.144cm^-1,ν₃(b₂)=2759.304cm^-1.AlH₂分子的稳态结构也为C_2v构型，电子态为²A₁、平衡核间距R_AlH=0.1592nm、键角∠HAlH=118.095°、离解能D_e=2.27eV、基态振动频率ν₁(a₁)=780.81cm^-1,ν₂(a₁)=1880.81cm^-1，ν₃(b₂)=1910.46cm^-1.采用多体项展式理论推导了基态BH₂和AlH₂分子的解析势能函数，其等值势能图准确再现了BH₂和AlH₂分子的结构特征及其势阱深度与位置.分析讨论势能面的静态特征时得到BH+H→BH₂反应中存在鞍点，活化能为150.204kJ/mol；AlH+H→AlH₂反应中也存在鞍点，活化能为54.8064kJ/mol. 关键词： 2')" href="#">BH₂ 2')" href="#">AlH₂ Murrell-Sorbie函数 多体项展式理论 解析势能函数     

SiO2分子的基态(X1A1)结构与分析势能函数

应用群论及原子分子反应静力学方法推导了SiO2分子的电子态及其离解极限,采用B3P86方法,在6-311G**水平上,优化出SiO2基态分子稳定构型为单重态的C2V构型,其平衡核间距Re=RSi-O=0.1587 nm,∠OSiO=111.2°,能量为-440.4392 a.u..同时计算出基态的简正振动频率:对称伸缩振动频率v(B2)=945.4cm-1,弯曲振动频率v(A1)=273.5 cm-1和反对称伸缩振动频率v(A1)=1362.9cm-1.在此基础上,使用多体项展式理论方法,导出了基态SiO2分子的全空间解析势能函数,该势能函数准确再现了SiO2(C2V)平衡结构.     

NiH2分子的结构及其势能函数

应用群论及原子分子反应静力学方法推导了NiH2分子基态的电子态及其离解极限,在MP2/6-311G水平上,优化出NiH2(3Δg)分子稳定构型为D∞h,其平衡核间距Re=0.157 3 nm、∠HNiH=180.00°,同时计算出振动频率:对称伸缩振动频率ν1=2 000 cm-1,弯曲振动频率ν2=721 cm-1和反对称伸缩振动频率ν3=1 875 cm-1.在此基础上,使用多体项展式理论方法,导出了基态NiH2分子的全空间解析势能函数,该势能函数准确地再现了NiH2(D∞h)平衡结构.     

SiO2分子的基态(X1A1)结构与分析势能函数

应用群论及原子分子反应静力学方法推导了SiO₂分子的电子态及其离解极限，采用B3P86方法，在6-311G^**水平上,优化出SiO₂基态分子稳定构型为单重态的C_2V构型，其平衡核间距R_e=R_Si—O=0.1587 nm,∠OSiO＝111.2°,能量为-440.4392 a.u..同时计算出基态的简正振动频率:对称伸缩振动频率ν(B₂)=945.4cm^-1，弯曲振动频率ν(A₁)=273.5 cm^-1和反对称伸缩振动频率ν(A₁)=1362.9cm^-1.在此基础上，使用多体项展式理论方法，导出了基态SiO₂分子的全空间解析势能函数，该势能函数准确再现了SiO₂(C_2V)平衡结构.     

AlB2和Al2B的结构与解析势能函数

运用单双取代耦合簇（CCSD）方法,选择基组6-311+g（2df）对基态B₂、Al₂分子和基组6-311g（3df）对基态AlB分子的微观结构进行优化计算,采用最小二乘法拟合得到B₂、Al₂和AlB分子的势能函数,并得到了与实验值符合很好的光谱常数.采用同种方法,选择6-31g基组,对基态AlB₂和Al₂B分子的结构进行优化计算.运用原子分子反应静力学原理得到离解极限.在此基础上,采用多体项展式法,得到AlB₂和Al₂B分子基态解析势能函数,该势能函数准确再现了AlB₂和Al₂B分子基态平衡结构特征.     

Si_3分子基态(X~1A_1)的结构与分析势能函数

应用群论及原子分子反应静力学方法推导Si分子的电子态及其离解极限,在B3P86/CC-PVTZ水平上,对Si3分子基态进行优化计算,得出Si3基态的单重态能量最低,其稳定构性为的C2V构型,平衡核间距Re=0.2176nm、∠213=79.7°,能量为-869.2057a.u..同时计算出基态的简正振动频率:对称伸缩振动频率ν(B2)=547.6446cm-1,弯曲振动频率ν(A1)=185.6100cm-1和反对称伸缩振动频率ν(A1)=559.6090cm-1.在此基础上,使用多体项展式理论方法,导出了基态Si3分子的全空间解析势能函数,该势能函数准确再现了Si3(C2V)平衡结构.     

N2O异构体结构与解析势能函数

在B3P86/cc-PVTZ水平上,对N₂O异构体进行优化计算,得出N₂O基态的单重态能量最低,其稳定构型为C_∞v构型,平衡核间距R₁=0.1121nm,R₂=0.1177nm,α＝180°,能量为-185.1188a.u.同时计算出基态的简正振动频率ω₁(Π)=601.5010 cm^{关键词： 异构体 多体项展式理论 解析势能函数}     

SiF2基态分子的结构与势能函数

运用Gaussian03软件包,采用密度泛函理论中的B3P86 方法,结合6-311++G**(3df,3pd)基组对基态SiF2分子的平衡电子结构和谐振频率进行了优化计算,得到了其稳定结构为C2v构型.SiF2基态电子态为X1A1,平衡核间距RSi-F=0.1061nm,键角αF-Si-F=100.6762°,离解能 De=13.8eV.应用多体项展式理论推导了基态SiF2分子的解析势能函数,其等值势能图准确地再现了SiF2分子的平衡构型特征和能量变化.     

LiO2(C2V，X2A2)分子的结构与势能函数

使用二次组态相互作用方法，在aug-cc-pvtz基组水平上对LiO₂(C_2V，X²A₂)基态分子进行了几何优化，得到了它的平衡几何构型和力常数.根据原子分子反应静力学原理得到可能的电子状态和离解极限.应用多体展式理论方法推导出了LiO₂(C_2V，X²A₂)基态分子的解析势能函数.     

SiF$lt;sub$gt;2$lt;/sub$gt;基态分子的结构与势能函数

运用Gaussian03软件包,采用密度泛函理论中的B3P86 方法,结合6-311++G^**（3df,3pd） 基组对基态SiF₂分子的平衡电子结构和谐振频率进行了优化计算,得到了其稳定结构为C_2v构型.SiF₂基态电子态为X¹A₁,平衡核间距R_Si—F=0.1061　nm,键角α_F—Si—F=100.6762°,离解能D_e=13.8　eV.应用多体项展式理论推导了基态SiF₂分子的解析势能函数,其等值势能图准确地再现了SiF₂分子的平衡构型特征和能量变化. 关键词： 2')" href="#">SiF₂ Murrell-Sorbie函数 多体项展式理论     

NiCO分子结构与解析势能函数

用密度泛函理论的B3P86方法,对镍原子采用LANL2DZ收缩价基,碳原子和氧原子采用6-311+G~*基组,对NiC、NiO和NiCO体系的结构进行优化,计算表明:NiC分子基态为~1∑~+态,键长为R_e=0.16070 nm,离解能为3.62948 eV.NiO分子基态的平衡核间距为0.16784 nm,其电子态为~3∑~-,离解能为3.45119 eV,拟合得到Murrell-Sorbie势能函数;NiCO分子有两个线性稳定构型,其中一个构型为Ni—C≡O(C_(∞υ)),电子态为~1∑~+,平衡核间距为R_(NiC)=0.16621 nm,R_(co)=0.11519 nm,离解能为12.80476 eV,另一个为Ni—O≡C(C_(∞υ)),电子态是~1∑~+,平衡核间距为R_(co)=0.11470 nm,R_(NiO)=0.17636 nm,离解能为11.24679 eV.由微观过程的可逆性原理分析了分子的可能的离解极限,并用多体展式理论导出基态NiCO分子的势能函数,其等势面图准确地再现了NiCO分子的结构特征和离解能,由此讨论了Ni+CO,NiC+O,NiO+C分子反应的势能面静态特征.     

Theoretical study of structure and analytic potential energy function for the ground state of PO2 molecule

In this paper, the energy, the equilibrium geometry, and the harmonic frequency of the ground electronic state of PO₂ are computed using B3LYP, B3P86, CCSD(T), and QCISD(T) methods in conjunction with 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 C_2v symmetry and its ground electronic state is X²A₁. The equilibrium parameters of the structure are R_P-O=0.1465 nm, d=19.218 eV. The bent vibrational frequency ν₁=386 cm^-1, the symmetric stretching frequency ν₂=1095 cm^-1, and the asymmetric stretching frequency ν₃=1333 cm^-1 are obtained. On the basis of atomic and molecular reaction statics, the reasonable dissociation limit for the ground state of the PO₂ molecule is determined. Then the analytic potential energy function of the PO₂ molecule is first derived by using the many-body expansion theory. The potential curves correctly reproduce the configurations and the dissociation energy for the PO₂ molecule.     

Na2H的基态结构与势能函数

采用二次组态相关(QCISD)方法对NaH分子进行理论计算,得到它的几何结构、光谱性质,并拟合出它的Murrell-Sorbie势能函数.应用密度泛函(B3LYP)方法,在6-311G(3df,3pd)基组水平上对Na2H分子的基态结构进行优化,并用同样的基组对该分子进行了进一步的频率计算.结果发现Na2H分子的基态稳态结构为C2v构型,采用多体项展式理论导出了它的解析势能函数,其等值势能图准确再现了Na2H分子的结构特征和离解能.并报导了该分子对称伸缩振动等值势能图中存在的两个对称鞍点,对应于反应NaH Na→Na2H,活化能大约为14.56 kJ/mol.     

Theoretical study of the structure and analytic potential energy function for the ground state of the PO2 molecule

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.     

The analytical potential energy function of flue gas SO2（X1A1）

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.     

The molecular structure and analytical potential energy function of HCO （X^2A＇）

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.     

Theoretical study of the structure and analytic potential energy function for the ground state of the PO₂ molecule

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 PO 2 molecule. It is shown that the ground state of the PO2 molecule has C2v symmetry and its ground electronic state is X2 A1 . The equilibrium parameters of the structure are R P O = 0.1465 nm, ∠OPO = 134.96°, and the dissociation energy is Ed = 19.218 eV. The bent vibrational frequency ν 1 = 386 cm-1 , symmetric stretching frequency ν 2 = 1095 cm-1 , and asymmetric stretching frequency ν 3 = 1333 cm-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.     

LiB2和Li2B分子的结构与势能函数

运用单双取代耦合簇(CCSD)方法,选择基组6-311+g(2df)对基态B2、Li2和LiB分子的微观结构进行优化计算,采用最小二乘法拟合得到B2、Li2和LiB分子的势能函数,并得到了与实验值符合很好的光谱常数.采用同种方法,选择6-311g基组对LiB2、6-31g基组对Li2B分子的基态结构进行优化计算.运用原子分子反应静力学原理得到离解极限.在此基础上,采用多体项展式法,得到LiB2和Li2B分子基态解析势能函数,该势能函数准确再现了LiB2和Li2B分子基态平衡结构特征.