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Geometrical structures, vibrational frequencies, force constants and dissociation energies of isotopic water molecules (H_2O, HDO, D_2O, HTO, DTO, and T_2O) under dipole electric field

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Chinese Physics B 2011年第6期20卷 174-181页

作者：史顺平张全张莉王蓉朱正和蒋刚傅依备 Institute of Atomic and Molecular Physics Sichuan University School of Mechanical Engineering & Automation Xihua University China Academy of Engineering Physics

The dissociation limits of isotopic water molecules are derived for the ground state. The equilibrium geometries, the vibrational frequencies, the force constants and the dissociation energies for the ground states of all isotopic water molecules under the dipole electric fields from -0.05 a.u. to 0.05 a.u. are calculated using B3P86/6-311＋＋G（3df,3pf）. The results show that when the dipole electric fields change from -0.05 a.u. to 0.05 a.u., the bond length of H-O increases whereas the bond angle of H-O H decreases because of the charge transfer induced by the applied dipole electric field. The vibrational frequencies and the force constants of isotopic water molecules change under the influence of the strong external torque. The dissociation energies increase when the dipole electric fields change from -0.05 a.u. to 0.05 a.u. and the increased dissociation energies are in the order of H2O, HDO, HTO, D2O, DTO, and T2O under the same external electric fields.

关键词： isotopic water molecules equilibrium geometry vibrational frequencies force constants dissociation energies

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Relativistic density functional investigation of UX_6(X=F,Cl,Br and I)

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Chinese Physics B 2010年第3期19卷 274-280页

作者：张云光李育德 School of Electronics and Information Engineering Sichuan University

The molecular structures and the vibrational frequencies of uranium hexahalides UX6 （X=F, Cl, Br and I） molecules are investigated by using local density approximation （LDA） and generalised gradient approximation （GGA） functions （BP, BLYP and RPBE） in combination with two different relativistic methods （scalar and scalar＋spin-orbit relativistic effects）. The calculated results show that the differences are trivial between scalar and scalar＋spin-orbit relativistic methods. The vibrational frequencies are also compared with existing experimental values, and overall, the RPBE approach gives the smallest error. The bond dissociation energies （BDEs） of UX6 are computed by using the RPBE function, thereby obtaining exact vibrational frequencies. In addition, the calculated magnitudes of the spin orbit effect on the BDE of UX6 （X=F, Cl, Br, and I） are found to be approximately -0.3198, 0.3218, -0.3609 and -0.4415 eV, respectively.

关键词： molecular structure vibrational frequencies bond dissociation energy spin-orbit cou-pling

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Franck-Condon Factors and Band Origins for MgH in the A2П-X2∑＋ System

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Chinese Journal of Chemical Physics 2015年第3期28卷 253-256,I0001页

作者： Xu Cheng Jiao Bai Jian-ping Yin Hai-ling Wang State Key Laboratory of Precision Spectroscopy East China Normal University ShanEhai 200052 China

We measure the dispersed spectrum of the A2H-X2E＋ system of MgH using laser abla- tion/laser induced Fluorescence method and obtain the Frank-Condon factors and related transition frequencies of the A2H（v＇=0）-X2∑＋（v＂=0,1） system by analyzing the experimental spectrum. Also, we calculate the Franck-Condon factors and transition frequencies of the A2H-X2∑＋ system of MgH. A comparison of our theoretical calculation and experimental results with other reported theoretical results was carried out as well.

关键词： Franck-Condon factors Energy curve vibrational frequencies Dispersed fluorescence

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Comparative Studies of 1,4-Bis[2-(4-Pyridyl)ethenyl]-benzene Using Density Functional Theory

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Chemical Research in Chinese Universities 2007年第4期23卷 469-473页

作者： CHENG Jian-bo Lǚ Jia-ping GONG Bao-an LI Wen-zuo Science and Engineering College of Chemistry and Biology Yantai University Yantai 264005 P. R. China

The optimized molecular structure and harmonic vibrational frequencies of a 1,4-bis [ 2-（4-pyridyl）ethenyl]- benzene（BPENB） molecule were calculated via five popular density functional theory（DFI＇） methods. On the basis of the comparison between calculated and experimental results, it is concluded that the B3PW91 and B3LYP methods are superior to the others in optimizing structures, and the BPW91 method reproduces the observed fundamental fre-quencies most satisfactorily.

关键词： 1,4-Bis[2-(4-pyridyl)ethenyl]-benzene Density functional theory vibrational frequencies BPW91

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Cryogenic Photodetachment Spectroscopy and High-Resolution Resonant Photoelectron Imaging of Cold para-Ethylphenolate Anions

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Precision Chemistry 2023年第3期1卷 161-174页

作者： Dao-Fu Yuan Yue-Rou Zhang Chen-Hui Qian Guo-Zhu Zhu Lai-Sheng Wang Department of Chemistry Brown UniversityProvidenceRhode Island 02912United States

Valence-bound molecular anions with polar neutral cores(μ>2.5 D)can support highly diffuse dipole-bound states(DBSs)as electronically excited states just below the detachment *** weakly bound nonvalence excited states have little influence on the structure of the neutral core,and they usually have the same vibrational *** can be systematically searched using photodetachment spectroscopy(PDS),which can yield the binding energies of the DBSs,the electron detachment threshold of the anion,and above-threshold vibrational levels of the DBSs(Feshbach resonances).We have shown that the combination of PDS and resonant photoelectron spectroscopy(rPES)at the Feshbach resonances is a powerful approach to obtain rich vibrational information for complex molecular radicals.A prerequisite for this technique is to produce vibrationally cold anions,made possible by a cryogenically controlled Paul *** this article,we report a PDS and rPES study of cold para-ethylphenolate anions(p-EP^(-)).The electron affinity of the p-EP radical is measured to be 17425±3 cm^(-1)(2.1604±0.0004 eV),and a DBS is found at 145 cm^(-1) below the detachment threshold of p-EP^(-).Thirty-four vibrational levels are observed for the DBS,including two bound levels and 32 Feshbach *** for 17 vibrational modes of the p-EP radical are measured from the combination of PDS and rPES,including six symmetry-forbidden modes with A″*** current study confirms again the power of combining cryogenic ion cooling with PDS and highresolution rPES to obtain spectroscopic information on complex molecular radicals.

关键词： dipole-bound state photoelectron imaging cryogenic ion cooling resonant photoelectron spectroscopy ethylphenoxy radical vibrational frequencies electrospray ionization

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Improved Energy Derivatives in the Generalized Energy-Based Fragmentation Approach

Improved Energy Derivatives in the Generalized Energy-Based ...

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中国化学会第29届学术年会

作者： Wei Li School of Chemistry and Chemical Engineering Nanjing University

The generalized energy-based fragmentation（GEBF）approach[1]has been implemented for the analytic total energy gradients as follow,[2]aETot/aqA=ΣnCn（aEn/aqA-Fn,aQa-Σbfab）+[（MΣmCm）-1]Σb∈allfab,（1）where A denotes a real atom in a given subsystem,a,b denote the point-charge centers,n,aF is the electric field generated by the n-th subsystem on the center a（which can be calculated with some existing ab initio programs）,and abf represents the Coulomb force between charge on b and charge on *** analytic energy gradients are shown to be more accurate than the approximate ones[3]and can be used for the geometry optimization and ab initio molecular dynamics（AIMD）for large systems.[2]A similar way is able to be applied to the second-order derivatives of the total energy with respect to nuclear displacements,*** matrix,which could be used for vibrational frequencies,intensities of normal modes,and various thermochemistry data（such as enthalpy,free energy,etc.）.In additional,based on the multilevel GEBF approach for total energy,[4]a multilevel GEBF-MP2method for energy gradients is developed.[5]

关键词： Generalized energy-based fragmentation approach Energy gradients Hessian matrix Ab initio molecular dynamics vibrational frequencies

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