dissociation, E, of a dimer into two monomers and that, E', of a trimer into a dimer and a monomer. The observed velocity distribution for a beam of sodium iodide is shown in Fig. 23. The monomer and dimer distributions, which are each of the form of Eq. (9. 2), are separately shown. The sum of the two assumed distributions is seen to agree with the experimental data. The data for lithium bromide are shown in Fig. 24. The separate distributions for the monomer, dimer, and trimer required to fit the data are shown as is the sum of these distributions. An attempt to describe the observed distribution in terms of a monomer and a dimer only is shown by the dotted line, where the relative amounts of these species have been adjusted to give a fit on the low velocity side of the spectrum. Table 2. Summary oj data on the degree of association oj diatomic molecules. The data on the fluorides are from unpublished results of M. EISENSTADT, G. ROTHBERG and P. KUSCH. Uncertainties in E and E' are given in parentheses. E E' Temperature OK I ----- ----" Species at which a2 a, kcaljmole p~10-2mmHg RbCl 866 0. 063 48. 0 (0. 5) I KCI 0. 083 897 45·8 (0. 7) I KI 823 0. 046 , 45·3 (0·9) NaC] 920 0. 259 44. 6 (0·9) i NaI 817 0. 235 38. 6 (3-4) LiC] 2.

Inhalt

Atomic and Molecular Beam Spectroscopy.- A. Methodology.- I. The beam.- a) Sources.- b) Beam characteristics.- c) Detectors.- II. Beam deflection.- a) General theory.- b) Deflecting fields.- III. The transition process.- B. Atomic spectroscopy.- I. Hyperfine structure.- a) General theory.- b) Methods of measurement and results.- II. Atomic magnetism and fine structure.- C. Molecular spectroscopy.- I. Unresolved molecular spectra by magnetic resonance method.- a) High field case.- b) Intermediate and low field cases.- II. Resolved molecular spectra by electric resonance method.- III. Resolved molecular spectra by magnetic resonance method.- Acknowledgment.- General references.- References to original papersc.- The Vibration-rotation Energies of Molecules and their Spectra in the Infra-red..- Symbols and notation used.- I. Introduction.- II. The general formulation of the quantum mechanics.- III. The quantum mechanical Hamiltonian for a polyatomic molecule.- IV. The energies of a polyatomic molecule.- V. The improved energies of a polyatomic molecule.- VI. The interpretation of the infrared spectra of molecules.- VII. Anomalies in the infrared spectra of molecules.- Acknowledgments.- The Collisions of Electrons with Molecules.- A. General theoretical considerations.- B. The elastic scattering of electrons by molecules.- C. Inelastic collisions of electrons with molecules.- D. Electronic excitation.- E. Excitation of molecular vibration and rotation.- F. Ionization of molecules.- G. Experimental data for ionization of diatomic molecules.- H. Experimental data for ionization of polyatomic molecules.- Acknowledgments.- Sachverzeichnis (Deutsch/Englisch).- Subject Index (English/German).