Coriolis coupling constants and inertial defect of B2F4 by ab initio calculations and the iterative method

1998 ◽  
Vol 76 (1) ◽  
pp. 57-61
Author(s):  
Marcos Loroño ◽  
J R Anacona ◽  
Anibal Sierralta
Keyword(s):  
Iterative Method ◽  
Ab Initio ◽  
Structural Parameters ◽  
Force Constants ◽  
Coupling Constants ◽  
Basis Set ◽  
Coriolis Coupling ◽  
Harmonic Frequencies ◽  
Wave Numbers ◽  
Rhf Calculations

Structural parameters, harmonic frequencies, and force constants of B2F4 were obtained in internal coordinates from ab initio RHF calculations with the 6-311G* basis set. The results obtained are used to calculate the Coriolis coupling constants and the inertial defect for 10B2F4 and 11B2F4 and to compare these values with those obtained by using the autoconsistency method. Both the ab initio and the iterative force fields, despite some significant differences, reproduce the vibrational wave numbers equally well and yield nearly the same Coriolis coupling constants and inertial defects. The calculated inertial defects for 10B2F4 and 11B2F4 are -0.942 and -0.919 amu Å2, respectively.Key words: Coriolis coupling constants, inertial defect, B2F4, harmonic frequencies, force constants.

Relation between Magnetic, Spectroscopic and Structural Properties of Binuclear Copper(II) Complexes of Pentadentate Schiff-base Ligand, Semi-empirical and ab-initio Calculations

2003 ◽  
Vol 58 (5-6) ◽  
pp. 363-372 ◽  
Author(s):  
Y. Elerman ◽  
H. Kara ◽  
A. Elmali
Keyword(s):  
Ab Initio ◽  
Coupling Constants ◽  
Antiferromagnetic Coupling ◽  
X Ray Diffraction ◽  
Hartree Fock ◽  
Ligand Orbital ◽  
Rhf Calculations ◽  
The Difference ◽  
Semi Empirical

The synthesis and characterization of [Cu2(L1)(3,5 prz)] (L1=1,3-Bis(2-hydroxy-3,5-chlorosalicylideneamino) propan-2-ol) 1 and of [Cu2(L2)(3,5 prz)] (L2=1,3-Bis(2-hydroxy-bromosalicylideneamino) propan-2-ol) 2 are reported. The compounds were studied by elemental analysis, infrared and electronic spectra. The structure of the Cu2(L1)(3,5 prz)] complex was determined by x-ray diffraction. The magnetochemical characteristics of these compounds were determined by temperaturedependent magnetic susceptibility measurements, revealing their antiferromagnetic coupling. The superexchange coupling constants are 210 cm−1 for 1 and 440 cm−1 for 2. The difference in the magnitude of the coupling constants was explained by the metal-ligand orbital overlaps and confirmed by ab-initio restricted Hartree-Fock (RHF) calculations. In order to determine the nature of the frontier orbitals, Extended Hückel Molecular Orbital (EHMO) calculations are also reported.

Vicinal proton—proton coupling constants. Basis set dependence in SCF ab initio calculations

1993 ◽  
Vol 206 (1-4) ◽  
pp. 253-259 ◽  
Author(s):  
Jesús San-Fabián ◽  
Joaquín Guilleme ◽  
Ernesto Díez ◽  
Paolo Lazzeretti ◽  
Massimo Malagoli ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Coupling Constants ◽  
Basis Set ◽  
Proton Proton ◽  
Proton Coupling ◽  
Vicinal Proton

Kraftkonstanten, mittlere Schwingungsamplituden, Coriolis-Kopplungskonstanten und thermodynamische Funktionen der Moleküle WOCl4 und WOBr4 / Force Constants, Mean Amplitudes, Coriolis Coupling Constants, Thermodynamic Functions, WOCl4 , WOBr4

1974 ◽  
Vol 29 (4) ◽  
pp. 620-623 ◽  
Author(s):  
W. Brockner ◽  
H. Hovdan ◽  
S. J. Cyvin
Keyword(s):  
Thermodynamic Functions ◽  
Ideal Gas ◽  
Force Constants ◽  
Coupling Constants ◽  
Coriolis Coupling ◽  
Mean Amplitudes Of Vibration ◽  
Amplitude Correction ◽  
Different Temperatures ◽  
Harmonic Oscillator Approximation ◽  
The Mean

A normal co-ordinate analysis of the molecules W 0Cl4 and WOBr4 has been carried out following W ilson’s FG matrix method. Valence force constants based on known (WOCl4) and estimated (WOBr4) molecular parameters have been evaluated. The results support the assignment of the known Raman spectra of W0Cl4 . Also the mean amplitudes of vibration and the perpendicular amplitude correction coefficients K have been computed for the temperatures T = 0 and T = 298 °K. Furthermore the Coriolis coupling constants of the ζz(EaxEb)- type have been determined. Some thermodynamic functions have also been calculated for an ideal gas state at one atmosphere pressure and different temperatures using the rigid rotor harmonic oscillator approximation.

The ab initio Calculation of Nuclear Quadrupole Coupling Constants with Special Reference to 33S

1992 ◽  
Vol 47 (1-2) ◽  
pp. 203-216 ◽  
Author(s):  
Michael H. Palmer
Keyword(s):  
Experimental Data ◽  
Ab Initio ◽  
Ab Initio Calculation ◽  
Coupling Constants ◽  
Basis Set ◽  
Equilibrium Geometry ◽  
Relaxation Methods ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
The Relationship

AbstractThe ab initio calculation of 33S nuclear quadrupole coupling constants (NQCC) for a range of S-containing compounds with S2, S4 and S6 bonding types is described. All of the calculations used a triple zeta valence + polarisation basis set (TZVP) of gaussian type orbitals; all of the molecules were studied at the TZVP equilibrium geometry. The electric field gradients (EFG) calculated were correlated with the experimental NQCC obtained by either microwave spectroscopy (MW), nuclear quadrupole resonance (NQR) or NMR relaxation methods; although the experimental data cover a wide diversity of chemical types over a long period of time, the slope of the relationship between the EFG (qii) and the NQCC (χii) yields a value for the 33S atomic quadrupole moment of - 0.064 barn, very close to recent calculations with a large atomic basis set, and to experimental data. The relationship between the EFG tensor components and the internal molecular structure features is discussed for a diverse series of molecules.

NORMAL MODES, CORIOLIS COUPLING, AND CENTRIFUGAL DISTORTION IN MOLECULES WITH NEARLY FREE INTERNAL ROTATION: CH3—C≡C—CH3 AND CH3—C≡C—SiH3

1967 ◽  
Vol 45 (12) ◽  
pp. 3867-3893 ◽  
Author(s):  
P. R. Bunker ◽  
J. T. Hougen
Keyword(s):  
Force Field ◽  
Internal Rotation ◽  
Energy Levels ◽  
Normal Modes ◽  
Force Constants ◽  
Coupling Constants ◽  
Torsional Angle ◽  
Coriolis Coupling ◽  
Centrifugal Distortion ◽  
Centrifugal Distortion Constants

In 1964 Duncan determined force fields for the molecules CH3—C≡C—CH3 and CH3—C≡C—SiH3 under the assumption that the force constants were not dependent on the torsional angle γ. In the first half of this paper we determine the quantitative effect of adding various γ-dependent force constants to Duncan's force field for CH3—C≡C—CH3. The results lead to complications concerning the symmetry species of the normal coordinates, the magnitude of the Coriolis coupling constants, and the calculation of the energy levels. The possible avoidance of these complications is discussed.In the second half of the paper a formalism is set up relating the rotational and torsional centrifugal distortion constants to the vibrational force field for certain molecules with nearly free internal rotation. Duncan's force field for CH3—C≡C—SiH3 is used to calculate some centrifugal distortion constants for that molecule and for CH3—C≡C—SiD3 on the assumption of completely free internal rotation. Good agreement is obtained between the quantities calculated here and the observed quantities determined by Kirchhoff and Lide.

Anharmonicity corrections from Coriolis coupling constants

1975 ◽  
Vol 28 (12) ◽  
pp. 2727 ◽  
Author(s):  
TR Ananthakrishnan ◽  
G Aruldhas
Keyword(s):  
Coupling Constants ◽  
New Method ◽  
Coriolis Coupling ◽  
Harmonic Frequencies ◽  
Anharmonicity Constants

A new method is suggested for calculating the ratios of harmonic frequencies for certain types of molecules and their isotopic forms by making use of Coriolis coupling constants. The method applies to cases where there are two distinct degenerate vibrations with the same species. The anharmonicity constants for these vibrations can then be evaluated.

Solvent Effect on the 195Pt NMR Properties in Pyridonate-Bridged PtIII Dinuclear Complex Derivatives by ab Initio Molecular Dynamics and Localized Orbital Analysis

2021 ◽  
Author(s):  
Patrick Rodrigues Batista ◽  
Lucas C Ducati ◽  
Jochen Autschbach
Keyword(s):  
Molecular Dynamics ◽  
Solvent Effect ◽  
Ab Initio ◽  
Chemical Shifts ◽  
Structural Parameters ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Ab Initio Molecular Dynamics ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling

An ab Initio molecular dynamics investigation of the solvent effect (water) on the structural parameters, electronic structure, 195Pt NMR spin-spin coupling constants (SSCCs) and chemical shifts of a series of...

scholarly journals Mean Amplitudes of Vibration, Force Constants and Coriolis Coupling Constants of ZXY2(C2v) and ZXY3(C3v) Type Molecules and Ions

1968 ◽  
Vol 23 (10) ◽  
pp. 1656-1660 ◽  
Author(s):  
A. Müller ◽  
B. Krebs ◽  
A. Fadini ◽  
O. Glemser ◽  
S. J. Cyvin ◽  
...  
Keyword(s):  
Force Constants ◽  
Coupling Constants ◽  
Coriolis Coupling ◽  
Mean Amplitudes Of Vibration

For a large number of ZXY3(C3v) and ZXY2(C2v) molecules and ions symmetry force constants, mean amplitudes of vibration for bonded and nonbonded distances and Coriolis coupling constantshave been calculated.

Sign in / Sign up

Export Citation Format

Share Document