Long-range Casimir-Polder-Feinberg-Sucher intermolecular potential at nonzero temperature

A method of determining the dissociation energy of a diatomic molecule from the rotational term value(s)of a single vibrational level lying near dissociation is derived and tested. It is based on expressions relating the characteristic near-dissociation behavior of the rotational constants Bv, Dv, Hv,… etc., to the asymptotically dominant inverse power contribution to the long range intermolecular potential. Application of this procedure to data for ground state D2 yields a dissociation energy of D0 = 36 748.88(±0.3)cm−1, in essentially exact agreement with the value Herzberg determined from the onset of continuum absorption in the vacuum u.v., 36 748.9(±0.4) cm−1. This agreement between results obtained from completely different observables appears to confirm the existence of a small discrepancy between experiment and the most recent theoretical nonadiabatic dissociation energy of Kolos and Wolniewicz, 36 748.2 cm−1.

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INTERMOLECULAR POTENTIALS IN LIQUID CRYSTALS: COMPARISON BETWEEN SIMULATIONS AND NMR EXPERIMENTS

International Journal of Modern Physics C ◽

10.1142/s0129183199000309 ◽

1999 ◽

Vol 10 (02n03) ◽

pp. 403-413 ◽

Cited By ~ 12

Author(s):

RAYMOND T. SYVITSKI ◽

JAMES M. POLSON ◽

E. ELLIOTT BURNELL

Keyword(s):

Liquid Crystals ◽

Long Range ◽

Short Range ◽

Intermolecular Forces ◽

Order Parameters ◽

Intermolecular Potential ◽

Nmr Data ◽

Long Range Interactions ◽

Orientational Ordering ◽

Best Fit

The anisotropic intermolecular forces responsible for the orientational ordering in liquid crystals are probed by comparing Monte Carlo (MC) simulations with experimental nuclear magnetic resonance (NMR) results for solutes in nematic liquid crystals. In a special liquid crystal mixture where all long-range interactions are assumed to be minimized, the models for short-range interactions which best fit NMR experimental solute order parameters also best fit solute order parameters from MC simulations of hard ellipsoids. This is taken as an indication that in this special mixture the intermolecular potential is dominated by short-range forces. However, for liquid crystals where long-range interactions are important, simulations of hard ellipsoids with point quadrupoles cannot reproduce even the gross effects observed with experimental NMR data.

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Diagrammatic expansion of the long-range intermolecular potential and the total contribution of the first hyperpolarizability

Chemical Physics Letters ◽

10.1016/0009-2614(74)80068-0 ◽

1974 ◽

Vol 28 (2) ◽

pp. 258-262

Author(s):

E. Bergmann

Keyword(s):

Long Range ◽

Intermolecular Potential ◽

First Hyperpolarizability ◽

Total Contribution

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Collision Energy Dependence of the Overall Rate Constant for the Reaction NH(a1Δ ) + HN3

Laser Chemistry ◽

10.1155/1995/20746 ◽

1995 ◽

Vol 15 (2-4) ◽

pp. 183-194 ◽

Cited By ~ 1

Author(s):

Akihiro Watanabe ◽

Katsuyoshi Yamasaki ◽

Ikuo Tokue

Keyword(s):

Long Range ◽

Rate Constant ◽

Rate Constants ◽

Collision Energy ◽

Time Dependent ◽

Intermolecular Potential ◽

Potential Approximation ◽

Initial Stage ◽

Vibrational Levels ◽

Hydrogen Azide

The overall rate constant for the reaction NH(a1Δ ) + HN3 has been determined by the laser photolysis of hydrogen azide (HN3) at 266 nm and 193nm. The visible emission from vibronically excited NH2(A˜2A1) was dispersed and its time-dependent profiles were measured at several wavelengths. The rate constants are dependent not only on the photolysis wavelengths but also on the vibrational levels of the NH2(A˜2A1) produced in the reaction. The intermolecular potential between NH(a1Δ) and HN3 was determined to be the form V(R) = –C/Rs (2 < s < 4, C: constant) from the analysis with a long-range potential approximation. The interaction between NH(a1Δ ) and HN3 is mainly governed by the dipoledipole interaction in the initial stage of the reaction.

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