共查询到17条相似文献,搜索用时 125 毫秒
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采用从头计算的多参考组态相互作用方法和含扩散基的3个基组aug-cc-PVXZ (X=D,T,Q) 计算了SO和ClO分子及其分子离子的势能曲线,确定了平衡几何结构、离解能,并采用Feller拟合递推方法得到了基函数为无穷大计算水平值. 确定了SO-,ClO+,ClO-分子离子的基态. 通过Murrell-Sorbie势能函数和最小二乘法拟合得到了解析势能函数. 基于所得的势能函数,通过解核运动的薛定谔方程得到振
关键词:
多参考组态相互作用
势能曲线
解析势能函数
光谱常数 相似文献
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采用量子力学从头算方法,运用二次组态相互作用QCISD(T)/aug-cc-pVTZ和电子相关单双耦合簇CCSD(T)/6-311++G(3df,2pd)研究了BeH,BeD,BeT分子基态的结构与势能函数,计算出了这些分子的光谱数据(ωe,ωeχe,Be,αe,De),结果与实验光谱数据吻合较好.这表明上述分子基态的势能函数可用经修正的Murrell-Sorbie+c6函数来表示.
关键词:
BeH
BeD
BeT分子基态
分子结构
势能函数 相似文献
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采用密度泛函理论的B3LYP方法和二次组态相互作用(QCISD(T))方法优化计算了OH分子基态(X2Π)的平衡结构、振动频率和离解能.根据原子分子反应静力学原理,导出了OH分子基态(X2Π)的合理离解极限,采用最小二乘法拟合Murrell-Sorbie函数得到了相应的势能函数和与该基态相对应的光谱常数(Be,αe,ωe和ωeχe),计算结果与实验数据符合得相当好.
关键词:
OH分子
2Π)')" href="#">基态(X2Π)
势能函数 相似文献
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采用量子力学从头算方法,运用二次组态相互作用方法QCISD(T)结合6-311++G(3df,2pd)基组对CaH,CaD分子基态进行了几何结构优化、计算出了它们的光谱数据(ωe、ωeχe、Be、αe、De),结果与实验光谱数据吻合较好,表明上述分子基态的势能函数可用Murrell-Sorbie函数来表示. 相似文献
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运用群论及原子分子反应静力学方法,推导了XY(H,Li,Na)分子基态的电子态及相应的离解极限.并采用密度泛函方法(B3LYP)和二次组态相互作用方法(QCISD)优化计算了XY(H,Li,Na)分子基态的平衡结构、振动频率和离解能.使用QCISD/6-311++G(3df,3pd)方法,对XY(H,Li,Na)分子基态进行了单点能扫描计算,采用最小二乘法拟合Murrell-Sorbie函数得到了相应的势能函数和与该基态相对应的光谱常数(Be,αe,ωe和ωeχe),计算结果与实验数据符合得相当好.
关键词:
组态相关方法
基态
势能函数 相似文献
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利用QCISD(T),SAC-CI方法和cc-pVQZ,aug-cc-pVTZ,6-311++G及6-311++G(3df,2pd)基组,对MgH分子的基态X2Σ+,第一简并激发态A2Π和第二激发态B2Σ+的结构进行优化计算.通过对4个基组计算结果进行比较,得出6-311++G(3df,2pd)基组为最优基组.使用
关键词:
分子结构与势能函数
激发态
Murrell-Sorbie函数
C6函数')" href="#">Murrell-Sorbie+C6函数 相似文献
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Theoretical study of structure and analytic potential energy function for the ground state of PO2 molecule 下载免费PDF全文
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 C2v symmetry and its ground electronic state is X2A1. The equilibrium parameters of the structure are RP-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. 相似文献
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Theoretical study of the structure and analytic potential energy function for the ground state of the PO<sub>2</sub> molecule 下载免费PDF全文
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. 相似文献
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使用Gaussian03程序包中的“对称性匹配簇/对称性匹配簇-组态相互作用”方法, 利用多个基组对7Li2分子23Σ+g态的平衡几何进行了优化计算. 同时, 在优化得到的平衡位置附近、于同一条件下通过精细的单点能扫描, 获得了相应基组下的平衡核间距. 发现两者的结果不一致,对不一致的原因进行了解释. 分析表明,由单点能扫描得到的平衡核间距应更为合理. 同时也得出了6-311++G(3df,3pd),6-311++G(2df,2pd) 及6-311++G(2df,pd)基组均为较优基组的结论.于2.5a0—37a0的范围内利用6-311++G(3df,3pd)基组进行单点能扫描并使用最小二乘法拟合出了该态的解析势能函数. 利用解析势能函数的物理意义并结合Rydberg-Klein-Rees方法, 计算出了其相应的谐振频率, 进而计算了其他光谱常数. 为便于比较和分析, 对基态也进行了相应的计算.利用得到的解析势能函数, 对23Σ+g态的振动能级及振动经典转折点也进行了计算.
关键词:
势能函数
谐振频率
振动能级
Murrell-Sorbie函数 相似文献
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根据群论及原子分子反应静力学的有关原理,推导了PS基态分子电子态及其合理的离解极限.采用Gaussian 03软件中的密度泛函理论B3LYP和B3P86结合6-311++G(3df,3pd)、6-311++G、6-311G(3df,3pd)、cc-p VTZ和D95基组,对PS分子基态平衡结构和谐振频率进行了计算.通过比较计算结果,发现B3P86方法结合cc-p VTZ基组计算所得结果与实验值最接近.在该水平下对PS分子的基态进行了单点势能扫描计算,利用正规方程组拟合三参数的Murrell-Sorbie函数和修正的Murrell-Sorbie+C6函数,得到了基态PS分子完整的势能函数与相应的光谱常数ωe、ωexe、Be和αe的值.计算结果表明,利用三参数的Murrell-Sorbie函数计算所得的光谱常数与实验数据吻合得更好. 相似文献
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SHI De-Heng MA Heng SUN Jin-Feng ZHU Zun-Lue 《理论物理通讯》2007,47(6):1114-1120
The reasonable dissociation limit for the G^1Ⅱg, state of dimer ^7Li2 is determined. The equilibrium internuclear distance, dissociation energy, harmonic frequency, vibrational zero energy, and adiabatic excitation energy are calculated using a symmetry-adapted-cluster configuration-interactlon method in complete active space in Gaussian03 program package at such numerous basis sets as 6-311 ++G, 6-311 ++G(2df,2pd), 6-311 ++G(2df, p), cc-PVTZ, 6- 311++G(3df,3pd), CEP-121G, 6-311++G(2df, pd), 6-311++G(d,p),6-311G(3df,3pd), D95(3df,3pd), 6-311++G(3df,2p), 6-311++G(2df), 6-311++G(df, pd) D95V++, and DGDZVP. The complete potential energy curves are obtained at these sets over a wide internuclear distance range and have least squares fitted to Murrell-Sorbie function. The conclnsion shows that the basis set 6-311++G(2df, p) is a most suitable one for the G^1Ⅱg state. At this basis set, the calculated spectroscopic constants Te, De, Eo, Re, ωe, ωeXe, ae, and Be are of 3.9523 eV, 0.813 06 eV, 113.56 cm^-1, 0.320 15 nm, 227.96 cm^-1, 1.6928 cm^-1, 0.004 436 cm^-1, and 0.4689 cm^-1, respectively, which are in good agreement with measurements whenever available. The total 50 vibrational levels and corresponding inertial rotation constants are for the first time calculated and compared with available RKR data. And good agreement with measurements is obtained. 相似文献