Dependence of the pure quadrupole resonance frequency on volume and temperature

Stahl, E. A.

doi:10.1063/1.431213

Cited by 3 publications

(1 citation statement)

References 7 publications

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“…For example, it gave incorrect results for the moments of inertia for the BrO 3 group in NaBrO 3 4 and KBrO 3 . 5 Kushida et al 6 21,22 will be compared with experiments in which the NQR frequency was measured as function of temperature holding the pressure constant. The proposed theory satisfies the theoretical requirement for a T 4 term.…”

Section: Introductionmentioning

confidence: 99%

Dependence of the pure quadrupole resonance frequency on temperature for KBrO₃

Stahl

Herzog

2003

Magnetic Reson in Chemistry

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Section: Introductionmentioning

confidence: 99%

Dependence of the pure quadrupole resonance frequency on temperature for KBrO₃

Stahl

Herzog

2003

Magnetic Reson in Chemistry

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Dependence of the pure quadrupole resonance frequency on temperature and molar specific heat for NaBrO₃

Stahl

Tipsword

1990

Magnetic Reson in Chemistry

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The molar specific heat of NaBrO, in the temperature range 4.2-336 K was determined experimentally and compared with the theory developed by Stahl and generalized in this paper. The relationship between the molar specific heat and temperature was explicitly studied and compared with results obtained by other workers. The method developed also produces the Debye temperature, a,,, the maximum angular frequency, w,, and the product Zw: of the BrO, group, where Z is the moment of inertia and w, is the lattice vibration. The relationships between the 79Br NQR frequency and temperature and between the NQR frequency and molar specific heat were obtained.KEY WORDS Pure quadrupole resonance frequency Molar specific heat Temperature dependence NaBrO, Soon after the discovery' of the pure quadrupole splitting of the nuclear spin energy levels in solids, Bayer' proposed a theory in which this nuclear quadrupole resonance (NQR) depended on temperature for a single mode of oscillation. His work was subsequently generalized by Kushida, and Wang4 for more than one mode of oscillation. The result was a theory which was able to describe gross experimental results but which failed in some detailed aspects. For example, it gave incorrect results for the moments of inertia for the BrO, group in NaBr0,' and KBrO, .6 Kushida et aL7 and Gutowsky and Williams* then showed that a correct theory must include a dependence on volume. In addition, Kushida et al. demonstrated the need for the theory to incorporate the Debye model, and Silva and Schemppg noted the theoretical requirement for a T4 term.Therefore, a better NQR theory was needed which showed the dependence on volume (or molar specific heat, which contains this volume dependence) and on temperature, and could be tested experimentally. Stahl" developed such a theory which incorporates the Debye model and satisfies the theoretical requirement for a T4 term. In this theory, the quadrupole resonance frequency for one mode of vibration is given by exp(ho,JkT) -1 X where vQ is the resonance frequency when T = 0 K, N o is Avogadro's number, Z is the moment of inertia, o1 is the angular frequency of the lattice, O, is the maximum angular frequency of the lattice and k is the Boltzmann constant. C , is the molar heat capacity at constant volume and is given by where x = h o JkT, R is the molar gas constant and @d is the Debye temperature. This model assumes that the asymmetry parameter, N = (qxx -q,,,,)/q,, , is zero. Equation (1) is limited to a single mode of oscillation. It can be generalized, following the same process that Kushida, used to generalize the Bayer' theory, to a result which holds for an arbitrary number of modes of oscillation :where I , is the nth moment of inertia and O, is the nth angular frequency of vibration. We measured the NQR frequency of Na7'Br0, as a function of temperature from 4.2 to 336 K. By comparing the data with Eqn (3), we were able to obtain 0, and Zw' and then C , as a function of temperature. For the bromate group, the summation on n in Eqn (3) takes ...

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FSGO model for core d electrons: Optimized structures for third row hydrides

Simons

Talaty

1977

The Journal of Chemical Physics

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A quantum mechanical representation of a full M electron shell, employing nine Gaussians in a tripyramidal arrangement, is developed to extend the floating spherical Gaussian orbital (FSGO) method to molecules containing heavy atoms. To demonstrate the computational capabilities of the approach, a series of ab initio calculations including geometry optimizations are reported for CuH, ZnH2, GaH3, GeH4, AsH3, H2Se, and HBr. Excluding CuH, the average difference between predicted and observed equilibrium bond lengths is 0.03 Å; errors in bond angles for AsH3 and HBr average to 2.6°. A set of rules for FSGO orbital exponents, analogous in form to Slater’s rules for STO’s, is deduced, and illustrations of the utility of the rules are given.

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Dependence of the pure quadrupole resonance frequency on volume and temperature

Cited by 3 publications

References 7 publications

Dependence of the pure quadrupole resonance frequency on temperature for KBrO₃

Dependence of the pure quadrupole resonance frequency on temperature for KBrO₃

Dependence of the pure quadrupole resonance frequency on temperature and molar specific heat for NaBrO₃

FSGO model for core d electrons: Optimized structures for third row hydrides

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Dependence of the pure quadrupole resonance frequency on volume and temperature

Cited by 3 publications

References 7 publications

Dependence of the pure quadrupole resonance frequency on temperature for KBrO3

Dependence of the pure quadrupole resonance frequency on temperature for KBrO3

Dependence of the pure quadrupole resonance frequency on temperature and molar specific heat for NaBrO3

FSGO model for core d electrons: Optimized structures for third row hydrides

Contact Info

Product

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About

Dependence of the pure quadrupole resonance frequency on temperature for KBrO₃

Dependence of the pure quadrupole resonance frequency on temperature for KBrO₃

Dependence of the pure quadrupole resonance frequency on temperature and molar specific heat for NaBrO₃