Higher order molecular spectroscopic constants and dipole moment derivatives for diatomic alkali halides

1982 ◽  
Vol 60 (8) ◽  
pp. 1187-1192 ◽  
Author(s):  
J. Shanker ◽  
H. B. Agrawal
Keyword(s):  
Dipole Moment ◽  
Energy Level ◽  
Alkali Halide ◽  
Alkali Halides ◽  
Higher Order ◽  
Spectroscopic Constants ◽  
Quantum Mechanical ◽  
Vibrational Quantum Number ◽  
Derivatives Of ◽  
Level Analysis

Higher order molecular spectroscopic constants γe and βe are calculated for diatomic alkali halide molecules using new polarizabilities derived recently from the Seitz–Ruffa (SR) energy level analysis. The results for 20 alkali halide diatomic molecules are obtained using the Rittner potential and three forms of repulsion, viz. the Born–Mayer repulsion, the Hellmann repulsion, and the Born–Lande repulsion form. The dependence of the dipole moment on the vibrational quantum number is studied by evaluating the first and higher order derivatives of dipole moment using the SR energy level analysis. The results obtained are discussed and compared with the available experimental data as well as with quantum-mechanical results obtained by Matcha.

Spectroscopic constants and potential-energy derivatives for diatomic molecules of alkali halides

1989 ◽  
Vol 67 (10) ◽  
pp. 974-976 ◽  
Author(s):  
A. A. S. Sangachin ◽  
J. Shanker
Keyword(s):  
Potential Energy ◽  
Diatomic Molecules ◽  
Alkali Halides ◽  
Higher Order ◽  
Spectroscopic Constants ◽  
Spectroscopic Constant ◽  
Energy Derivatives ◽  
Internuclear Distances ◽  
Experimental Values

The potential-energy derivatives are derived directly from the experimental values of the spectroscopic constants for diatomic alkali halides. It is found that these derivatives are useful in predicting more accurately the values of the higher order spectroscopic constant (βe). Some interesting new relations showing the dependence of the potential-energy derivatives on internuclear distances have been investigated empirically. An attempt has been made to interpret these relations on the basis of interionic potentials.

scholarly journals Preparation and the Microwave and Infrared Spectra of Vinyl Ketene

1979 ◽  
Vol 34 (11) ◽  
pp. 1269-1274 ◽  
Author(s):  
Erik Bjarnov
Keyword(s):  
Dipole Moment ◽  
Gas Phase ◽  
Infrared Spectra ◽  
Room Temperature ◽  
Normal Modes ◽  
Spectroscopic Constants ◽  
Electrical Dipole ◽  
Electrical Dipole Moment ◽  
Vacuum Pyrolysis ◽  
Modes Of Vibration

Vinyl ketene (1,3-butadiene-1-one) has been synthesized by vacuum pyrolysis of 3-butenoic 2-butenoic anhydride. The microwave and infrared spectra of vinyl ketene in the gas phase at room temperature have been studied. The trans-rotamer has been identified, and the spectroscopic constants were found to be Ã= 39571(48) MHz, B̃ = 2392.9252(28) MHz, C̃ = 2256.0089(28) MHz, ⊿j = 0.414(31) kHz, and ⊿JK = - 34.694(92) kHz. The electrical dipole moment was found to be 0.987(23) D with μa = 0.865(14) D and μb = 0.475(41) D. A tentative assignment has been made for 17 of the 21 normal modes of vibration

A C0 three-node triangular element based on preprocessing approach for thick sandwich plates

2017 ◽  
Vol 21 (6) ◽  
pp. 1820-1842
Author(s):  
Wu Zhen ◽  
Ma Rui ◽  
Chen Wanji
Keyword(s):  
Transverse Shear ◽  
Equilibrium Equation ◽  
Three Dimensional ◽  
Higher Order ◽  
Triangular Element ◽  
Shear Stresses ◽  
Sandwich Plates ◽  
Transverse Shear Stress ◽  
Transverse Shear Stresses ◽  
Derivatives Of

This paper will try to overcome two difficulties encountered by the C0 three-node triangular element based on the displacement-based higher-order models. They are (i) transverse shear stresses computed from constitutive equations vanish at the clamped edges, and (ii) it is difficult to accurately produce the transverse shear stresses even using the integration of the three-dimensional equilibrium equation. Invalidation of the equilibrium equation approach ought to attribute to the higher-order derivations of displacement parameters involved in transverse shear stress components after integrating three-dimensional equilibrium equation. Thus, the higher-order derivatives of displacement parameters will be taken out from transverse shear stress field by using the three-field Hu–Washizu variational principle before the finite element procedure is implemented. Therefore, such method is named as the preprocessing method for transverse shear stresses in present work. Because the higher-order derivatives of displacement parameters have been eliminated, a C0 three-node triangular element based on the higher-order zig-zag theory can be presented by using the linear interpolation function. Performance of the proposed element is numerically evaluated by analyzing multilayered sandwich plates with different loading conditions, lamination sequences, material constants and boundary conditions, and it can be found that the present model works well in the finite element framework.

Expansions of the mildly relativistic dispersion function for nearly perpendicular electron cyclotron ray tracing

1999 ◽  
Vol 61 (1) ◽  
pp. 121-128 ◽  
Author(s):  
I. P. SHKAROFSKY
Keyword(s):  
Ray Tracing ◽  
Computer Programs ◽  
Higher Order ◽  
Electron Cyclotron ◽  
Dispersion Function ◽  
Relativistic Dispersion ◽  
Plasma Dispersion ◽  
Derivatives Of ◽  
Cyclotron Harmonic ◽  
Experienced Difficulty

To trace rays very close to the nth electron cyclotron harmonic, we need the mildly relativistic plasma dispersion function and its higher-order derivatives. Expressions for these functions have been obtained as an expansion for nearly perpendicular propagation in a region where computer programs have previously experienced difficulty in accuracy, namely when the magnitude of (c/vt)2 (ω−nωc)/ω is between 1 and 10. In this region, the large-argument expansions are not yet valid, but partial cancellations of terms occur. The expansion is expressed as a sum over derivatives of the ordinary dispersion function Z. New expressions are derived to relate higher-order derivatives of Z to Z itself in this region of concern in terms of a finite series.

Studies on the freezing of pure liquids I. Critical supercooling in molten alkali halides

1960 ◽  
Vol 259 (1298) ◽  
pp. 325-340 ◽  
Keyword(s):  
High Temperature ◽  
Critical Temperature ◽  
Melting Point ◽  
Alkali Halide ◽  
Alkali Halides ◽  
Solid Particles ◽  
High Supersaturation ◽  
Chamber Temperature ◽  
Reduced Temperature ◽  
Heater Coil

A high-temperature cloud chamber is described in which a bead of alkali halide is supported on a heater coil mounted in the roof. By passing the current through the coil the temperature of the bead may be momentarily raised by several hundred degrees, producing salt vapour at high supersaturation. Condensation ensues in the presence of the inert supporting gas, and clouds of droplets or solid particles appear depending on the chamber temperature. Light scattered from the clouds under strong illumination is examined with a telescope, and the presence of crystalline particles is detected by their capacity to scintillate, or ‘twinkle’. It is found that twinkling in clouds of alkali halides appears sharply as the temperature is lowered below the melting point, defining a critical temperature of solidification for each salt. Reasons are given for regarding this temperature as the freezing threshold of molten salt droplets, for which supercoolings of about 150 °C are indicated. A reduced temperature, given by the ratio of the freezing threshold to the melting point, has the value of approximately 0.8 for all the alkali halides examined.

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