Perturbations in the Spectra of Diatomic molecules

Perturbations in the Spectra of Diatomic Molecules examines in sufficient detail the spectrum of every diatomic molecule.

This book is divided into seven chapters. Chapter 1 describes the perturbations and simple procedures for evaluating matrix elements of angular momentum. The terms in the molecular Hamiltonian that are responsible for perturbations are elaborated in Chapter 2, while the process of reducing spectra to molecular constants and the difficulty of relating empirical parameters to terms in the exact molecular Hamiltonian are described in Chapter 3. Chapter 4 discusses the magnitudes and physical interpretations of matrix elements. The transition intensities, especially quantum mechanical interference effects, are reviewed in Chapter 5. The last two chapters are devoted to the two forms of perturbation—predissociation and autoionization.

This publication is a good source for graduate students, theorists, experimentalists, and potential users of spectroscopic data.

Preface

Chapter 1 Introduction

1.1 What Is a Perturbation?

1.2 Structural Models

1.3 Elementary Properties of Angular Momenta in Diatomic Molecules

1.4 Estimation of Parameters in a Model Hamiltonian

Data Compilations

References

Chapter 2 Terms Neglected in the Born-Oppenheimer Approximation

2.1 The Born-Oppenheimer Approximation

2.2 Basis Functions

2.3 Electrostatic Perturbations

2.4 Spin Part of the Hamiltonian

2.5 Rotational Perturbations

References

Chapter 3 Methods of Deperturbation

3.1 Variational Calculations

3.2 The Van Vleck Transformation and Effective Hamiltonians

3.3 Approximate Solutions

3.4 Exact Solutions

3.5 Typical Examples of Fitted Perturbations

References

Chapter 4 Interpretation of the Perturbation Matrix Elements

4.1 Calculation of the Vibrational Factor

4.2 Order of Magnitude of Electrostatic Perturbation Parameters: Interactions between Valence and Rydberg States of the Same Symmetry

4.3 Order of Magnitude of Spin Parameters

4.4 Order of Magnitude of Rotational Perturbation Parameters

4.5 Pure Precession Approximation

4.6 R-Dependence of the Spin Interaction Parameters

4.7 Beyond the Single-Configuration Approximation

4.8 Identification and Location of Metastable States by Perturbation Effects

References

Chapter 5 Effects of Perturbations on Transition Intensities

5.1 Intensity Factors

5.2 Intensity Borrowing

5.3 Interference Effects

5.4 Forbidden Transitions; Intensity Borrowing by Mixing with a Remote Perturber

5.5 Special Effects

References

Chapter 6 Predissociation

6.1 Introduction to Predissociation

6.2 Experimental Aspects of Predissociation

6.3 Theoretical Expressions for Widths and Level Shifts

6.4 Mulliken's Classification of Predissociations

6.5 The Vibrational Factor

6.6 The Electronic Interaction Strength

6.7 Interference Effects

6.8 Isotope Effects

6.9 Examples of Predissociation

6.10 Case of Intermediate Coupling Strength

6.11 Indirect (Accidental) Predissociation

6.12 Some Recipes for Interpretation

References

Chapter 7 Autoionization

7.1 Experimental Aspects

7.2 The Nature of Autoionized States

7.3 Autoionization Widths

7.4 Rotational Autoionization

7.5 Vibrational Autoionization

7.6 Spin-Orbit Autoionization

7.7 Electronic (or Electrostatic) Autoionization

7.8 Validity of the Approximations

References

Index