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1.
V. I. Tyulin G. M. Kuramshina Yu. A. Pentin Le Hyu Ho 《Journal of Structural Chemistry》1997,38(2):231-235
The direct and inverse vibrational problems are solved for the rotational isomers of the glyoxal and oxalyl halide molecules
in the ground and first excited singlet states.
Translated from Zhurnal Strukturnoi Khimii, Vol. 38, No. 2, pp. 287–292, March–April, 1997. 相似文献
2.
A. I. Pavlyuchko 《Journal of Structural Chemistry》1995,36(2):210-224
A new method is suggested for separating the vibrational, rotational, and translational motions of polyatomic molecules using
curvilinear vibrational coordinates that are linear with respect to the natural vibrational coordinates. It is shown that,
in this case, Coriolis interactions between the vibrational and rotational motions are absent. The solutions of the anharmonic
vibrational-rotational problems in the curvilinear and linear vibrational coordinates are compared. The absence of Coriolis
interactions between the vibrational and rotational motions in the curvilinear vibrational coordinates is proved numerically.
The same conclusion is additionally supported by calculations of the anharmonic vibrational energy levels for the H2O, H2S, NO2, SO2, and ClO2 molecules in the linear and curvilinear vibrational coordinates using the Hamiltonian designed in the curvilinear vibrational
coordinates with and without Coriolis vibrational-rotational interactions.
Volgograd Pedagogical University. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 2, pp. 239–254, March–April, 1995.
Translated by I. Izvekova 相似文献
3.
K. V. Mikhailova 《Journal of Structural Chemistry》1995,36(2):265-270
Correct assignment of calculated and experimental frequencies, as well as corservation of the initial assignment in case of
a random coincidence of two frequencies during the solution of an inverse spectral problem, are important problems in spectroscopy
of polyatomic molecules. Vibrations are classified according to their form, which is thought to be a more reliable basis for
assignment than frequency. We offer a PC program to determine the type of vibrations according to their form (obtained by
solving a direct vibrational problem) in a given system of vibrational basis set functions. Optimization of systems of basis
set functions for molecules with six-membered rings is discussed.
L. Ya. Karpov Physicochemical Scientific Research Institute. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 2, pp. 298–303, March–April, 1995.
Translated by L. Smolina 相似文献
4.
T. G. Burova 《Journal of Structural Chemistry》1997,38(2):201-206
A direct method for calculating the resonance Raman and two-photon absorption spectra of polyatomic molecules is described
in detail The method is based on the adiabatic model and uses Herzberg-Teller’s approximation. Relations ruling out direct
summation over vibrational quantum numbers of excited electronic states and representing the matrix elements of the Green
function of a multidimensional oscillator as functions of vibration frequencies and Dushinsky transformation parameters are
derived. The relations are convenient for constructing algorithms.
Translated from Zhumal Struktumoi Khimii, Vol. 38, No. 2, pp. 248–255, March–April, 1997. 相似文献
5.
A new algorithm for automatic assignment of the resolved vibrational structure of the electronic absorption spectra of diatomic
and polyatomic molecules is suggested.
Translated fromZhurnal Struktumoi Khimii, Vol. 38, No. 2, pp. 363–368, March–April, 1997. 相似文献
6.
The absorption spectra of decapentaene are analyzed and calculated using the available efficient methods of calculating the
matric elements of the vibronic problem, a new parametric method for determining the potential surfaces of excited molecules,
and a fragmentation approach to the design of molecular models. Good agreement for the fine vibrational structure of the calculated
and experimental spectra (differences between the main band frequencies and intensities less than 20 cm−1 and 10%, respectively) is obtained without correcting the parameters of the method. The mechanisms of excitation-induced
structural changes in linear polyenes and the effect of bond angle changes on the vibrational structure of the spectrum are
revealed. A new interpretation of the absorption spectrum of decapentaene in an argon matrix is proposed [J. Mol. Spectrosc.,114, 54–59 (1985)]. It is shown that the parametric method allows quantitative prediction of fine structure for the vibronic
spectra of complex molecules.
K. A. Timiryazev Moscow Agricultural Academy. Translated fromZhurnal Strukturmoi Khimii, Vol. 37, No. 6, pp. 1031–1039, November–December, 1996.
Translated by I. Izvekova 相似文献
7.
Yu. I. Naberukhin V. A. Luchnikov G. G. Malenkov E. A. Zheligovskaya 《Journal of Structural Chemistry》1997,38(4):593-600
The local structure of the molecular- dynamic model of water (729 particles at 300 K) is analyzed by isolating molecules whose
surroundings differ slightly in configuration from a regular tetrahedron. These molecules are not randomly distributed in
space but form nanometer clusters having a fractal structure. In these clusters, molecules are less mobile than the model
molecules in general;their self- correlation function of rate and the density of vibrational states also differ from the average characteristics of
the system.
Translated fromZhumal Strukturnoi Khimii, Vol. 38, No. 4, pp. 713–722, July–August, 1997. 相似文献
8.
L. S. Khaikin O. E. Grikina B. I. Zhilinskii E. A. Zhilinskaya E. G. Baskir R. V. Nepomnyashchii O. A. Fomicheva M. V. Proskurnina 《Russian Chemical Bulletin》1998,47(9):1653-1665
The equilibrium geometric parameters and structures of transition states of internal rotation for the molecules of methyldicyanophospine
MeP(CN)2 and its isocyano analog MeP(NC)2 were calculated by the RHF and MP2 methods with the 6–31G* and 6–31G** basis sets. At the MP2 level, the total energy of cyanide is −35 kcal mol−1 lower than that of isocyanide and the barriers to internal rotation of methyl group for MeP(CN)2 and MeP(NC)2 are 2.2 and 2.7 kcal mol−1, respectively. For both molecules, the one-dimensionalab initio potential functions of internal rotation approximated by a truncated Fourier series were used to determine the frequencies
of torsional transitions by solving direct vibrational problems for a non-rigid model. The Raman spectrum of crystalline MeP(CN)2 was recorded in the range 3500–50 cm−1. The vibrational spectra of this compound were interpreted by scalingab initio force fields calculated by the RHF and MP2 method. The vibrational spectrum of methyldiisocyanophosphine was predicted with
the use of the obtained scale factors.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1703–1714, September, 1998. 相似文献
9.
The parameters of the adiabatic model of the stilbene molecule in the excited state and the vibrational structure of the fluorescence
spectrum are calculated by the parametric method of the theory of vibronic spectra of complex molecules. The first and second
orders of theory are used. The molecular models are constructed by the fragment method. Satisfactory agreement with experiment
is obtained. The parameters of molecular fragments are shown to be highly transferable. The model and the spectrum max be
refined in the second order of theory using only one additional parameter for CCC angles (optimal values were obtained). The
parametric method under discussion makes it possible to predict variations of structural parameters due to excitation and
to calculate the vibrational structure of the electronic spectra of complex molecules, including characteristic variations
of the spectra in series of related molecules (stilbene-di-phenylpolyenes). This method surpasses all previous procedures
(in particular, the correlation method) in completeness and accuracy of results.
Translated fromZhurnal Strukturnoi Khinii, Vol. 41, No. 2, pp. 369–378, March–April, 2000. 相似文献
10.
An inverse problem on calculating the force field parameters of a molecule from experimental data and its solution using regularizing
algorithms are considered The choice of a priori constraints that may be imposed on solutions of the inverse vibrational problem
is analyzed in terms of quantum mechanical calculations of some polyatomic molecules at different levels of theory, including
electron correlation.
Translated from Zhumal Struktumoi Khimii, Vol. 38, No. 2, pp. 221–239, March–April, 1997. Original article submitted June
14, 1996. 相似文献
11.
Debbie J. Beard Sumer A. Barakat Nathanael B. Lockhart Chandler R. Pace Charles U. Pittman Jr. Burnette W. Hamil Svein Saebo 《Structural chemistry》2012,23(2):351-357
A systematic computational study of four-membered cyclic ketene –O,O–, –O,S–, –O,N–, –S,N– and –N,N-acetals as well as their protonated analogs have been performed at the second order M?ller Plesset level with a polarized
triple zeta basis set. The main purpose of this study was to make predictions about the nucleophilicity of these systems and
the variations in nucleophilicity with the hetero atoms. Our calculations suggest that all six target molecules are good nucleophiles,
and that the N,N analog is the strongest and the S,S analog the weakest nucleophile. Our results include molecular geometries, bond lengths, proton affinities, vibrational frequencies,
and calculated charges. 相似文献
12.
Mathew D. Halls Julia Velkovski H. Bernhard Schlegel 《Theoretical chemistry accounts》2001,105(6):413-421
Scaling factors for obtaining fundamental vibrational frequencies from harmonic frequencies calculated at six of the most
commonly used levels of theory have been determined from regression analysis for the polarized-valence triple-zeta (pVTZ)
Sadlej electric property basis set. The Sadlej harmonic frequency scaling factors for first- and second-row molecules were
derived from a comparison of a total of 900 individual vibrations for 111 molecules with available experimental frequencies.
Overall, the best performers were the hybrid density functional theory (DFT) methods, Becke's three-parameter exchange functional
with the Lee–Yang–Parr fit for the correlation functional (B3-LYP) and Becke's three-parameter exchange functional with Perdew
and Wang's gradient-corrected correlation functional (B3-PW91). The uniform scaling factors for use with the Sadlej pVTZ basis
set are 0.9066, 0.9946, 1.0047, 0.9726, 0.9674 and 0.9649 for Hartree–Fock, the Slater–Dirac exchange functional with the
Vosko–Wilk–Nusair fit for the correlation functional (S-VWN), Becke's gradient-corrected exchange functional with the Lee–Yang–Parr
fit for the correlation functional (B-LYP), B3-LYP, B3-PW91 and second-order M?ller–Plesset theory with frozen core (MP2(fc)),
respectively. In addition to uniform frequency scaling factors, dual scaling factors were determined to improve the agreement
between computed and observed frequencies. The scaling factors for the wavenumber regions below 1800 cm−1 and above 1800 cm−1 are 0.8981 and 0.9097, 1.0216 and 0.9857, 1.0352 and 0.9948, 0.9927 and 0.9659, 0.9873 and 0.9607, 0.9844 and 0.9584 for
Hartree–Fock, S-VWN, B-LYP, B3-LYP, B3-PW91 and MP2(fc), respectively. Hybrid DFT methods along with the Sadlej pVTZ basis
set provides reliable theoretical vibrational spectra in a cost-effective manner.
Received: 22 May 2000 / Accepted: 30 August 2000 / Published online: 28 February 2001 相似文献
13.
R. G. Zhbankov V. M. Andrianov H. Ratajczak M. Marchewka 《Journal of Structural Chemistry》1995,36(3):404-415
The IR and Raman spectra of β- and α-methyl-D-glucosides and β-methyl-D-xyloside are compared. Experimental data are correlated
with theoretical calculations of the frequencies of normal vibrations. Predominant contributions (20% and more) of particular
CiOi and CiC(i+1) bonds to the potential energy distribution of normal vibrations (i.e., localization of vibrations on these
bonds, which form skeletons of monosaccharide molecules) are estimated. This approach is used to interpret the main distinctions
between the IR and Raman spectra of the test compounds. The use of vibrational spectra in selective analysis of certain functional
groups is discussed. It is shown that replacing the hydroxyl group at C1 has a specific effect on the predominant localization
of vibrational modes in particular skeletal bonds (mainly in C1O1) of the monosaccharide molecules.
B. I. Stepanov Institute of Physics, Belarus Academy of Sciences. V. Tshebyatovski Institute of Low Temperatures and Structural
Studies, Polish Academy of Sciences. Translated fromZhurmal Strukturnoi Khimii, Vol. 36, No. 3, pp. 443–455. May–June, 1995.
Translated by I. Izvekova. 相似文献
14.
The vibrational structure of the electron transition to the second singlet excited state of pyridine N-oxide has been studied.
The frequency of the 0–0 transition is 34502 cm−1. A computer-aided technique for the assignment of the frequencies of the normal vibrations of polyatomic molecules in the
excited electronic states is proposed. The frequencies of the totally symmetric vibrations of pyridine N-oxide in the second
singlet electronically excited state are assigned.
N. G. Chernyshevskii Saratov State University. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 2, pp. 350–355, March–April, 1995.
Translated by I. Izvekova 相似文献
15.
Sh. Sh. Nabiev I. I. Ostroukhova N. V. Revina L. P. Sukhanov 《Russian Chemical Bulletin》1997,46(5):921-927
The Raman spectra of compounds R2NPX2 (R=Me and Et; X=F, Cl, and Br) were studied. The time correlation functions of vibrational and rotational relaxations as
well as the characteristic times of these processes were calculated. Conclusions concerning the mechanisms of formation of
the contours of the Raman lines with frequencies in the 670–705 cm−1 range corresponding to the totally symmetric vibrations of the P-N bond in the R2NPX2 molecules were drawan.
Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 961–967, May 1997. 相似文献
16.
N. V. Goncharova E. A. Nikitina V. D. Khavryuchenko E. F. Sheka 《Journal of Structural Chemistry》1995,36(1):50-59
This paper deals with computational modeling of structure and properties of the silicon nitride surface zone using combined
computational and real experiments. The computational experiment implies quantum chemical calculations of structure and vibrational
spectra of polyatomic clusters. The real experiment suggests measurement and analysis of vibrational spectra. For quantum
chemical calculations, semiempirical methods (MNDO and AM1) were chosen. In most calculations, the MNDO/H method was preferred
because of the presence of many H-bonds in the surface zone. For verification of calculations, we calculated the structures
and vibrational spectra of water and ammonia molecules and the water-ammonia complex and compared the results with experimental
and ab initio (extended basis) data; MNDO/H proved to be an optimal method giving reliable results.
Russian Peoples' Friendship University. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 1, pp. 58–69, January–February, 1995.
Translated by L. Smolina 相似文献
17.
D. Yu. Zelentsov 《Journal of Structural Chemistry》1997,38(2):195-200
The previously suggested approximate method for calculating the overlap integrals of vibrational wave functions is considerably
improved for the purpose of maximally accurate calculation of excitation-induced mixing of normal coordinates. A general formula
is obtained for all types of overlap integrals as a finite power series of the potential surface shift parameters; the coefficients
are derivatives of the corresponding generating Junctions represented as polynomials of the shift vector elements of the normal
coordinates and the mixing matrix. The spectra of model molecules of decatetraene and tetra- and hexadecaheptaene were calculated
using the expressions derived in this work and a semiempirical parametric method for determination of excitation-induced changes
in the potential surface of molecules. The calculations confirmed the high efficiency of both the parametric method and the
new technique.
Translated fromZhumal Strukturnoi Khimii, Vol. 38, No. 2, pp. 240–247, March–April, 1997. 相似文献
18.
A model of an early transition state with charge transfer is proposed for calculation of the activation parameters of the
abstraction of a hydrogen atom by peroxyl radicals from the molecules of organic compounds. It was shown that the compensation
effect in this reaction is due to the fact that the change in the preexponential factor is determined by change in the vibrational
component of the entropy of activation.
L. M. Litvinenko Institute of Physical Chemistry and Coal Chemistry, Academy of Sciences of Ukraine, Donetsk. Translated from
Teoreticheskaya i éksperimental’naya Khimiya, Vol. 33, No. 1, pp. 6–11, January–February, 1997. 相似文献
19.
N. M. Pozdeev A. Kh. Mamleev L. N. Gunderova R. V. Galeev G. R. Garipova V. I. Tyulin 《Journal of Structural Chemistry》1995,36(3):380-385
The microwave spectra of s-cis-glyoxal molecules in the excited states of torsional (vt=1,2) and bending (vbend=1) vibrations have been studied. For the vt=1 state, the rotational constants have been refined and the quartic constants of centrifugal distorition have been determined.
For the excited vt=2 and vbend=1 states, the rotational constants have found. For the ground vibrational state, the rotational constants and the quartic
constants of centrifugal distortion have been refined. The vibrational frequencies have been determined from the relative
intensities of rotational transitions.
Ufa Scientific Center of Russian Academy of Sciences, Physics Department. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 3, pp.418–423, May–June, 1995.
Translated by I. Izvekova 相似文献
20.
The structures of the perylene molecule in the first excited 11 0B2u state and the band shape (vibrational structure) of its fluorescence and absorption spectra are computed by the parametric
method. A fragmentary approach and the molecular fragments H/1C= with the parameters obtained for acenes and polyenes are
used to form molecular models in the excited state. It is shown that a model that corresponds to the choice of fragments with
the parameters of acenes is the most optimal. The theoretical spectra satisfactorily reproduce both qualitatively and quantitatively,
the basic specific features of the vibrational structure of the experimental spectra. Calculation results show high degree
of transfer of the parameters of the method in a series of related molecules not only for acenes with “linear” arrangement
of the rings (benzene, naphthalene, anthracene, etc.) but also for more complex structures (perylene). It is shown that the
parametric method developed is efficient for predicting the vibronic spectra and the structure of the excited states of complex
molecules.
Translated fromZhurnal Struktumoi Khimii, Vol.40, No. 2, pp. 242–250, March–April, 1999. 相似文献