Foreword xi
Jonathan TENNYSON

Introduction xv
Iwona GULACZYK, Michaël REY and Ha TRAN

Chapter 1. Quantities and Units in Spectroscopy 1
Vincent BOUDON and Cyril RICHARD

1.1. Introduction 1
1.2. Energy and associated quantities 2
1.3. Intensity 3
1.4. Line shape quantities 7
1.5. Other quantities 8
1.6. References 8

Chapter 2. Accounting for the Anomalous Centrifugal Distortion of the Water Molecule 11
Laurent H. COUDERT

2.1. The bending-rotation approach 13
2.2. The fitting bending-rotation approach 21
2.3. Extended version of the fitting bending-rotation approach 24
2.4. References 24

Chapter 3. Hindered Torsion of Asymmetrical Groups 27
Laurent H. COUDERT

3.1. Torsion of an asymmetrical top 29
3.2. The fitting Hamiltonians 36
3.3. References 41

Chapter 4. Coupled Large Amplitude Motions 45
Isabelle KLEINER, Iwona GULACZYK and Marek KREGLEWSKI

4.1. Introduction 45
4.2. Theory for one LAM 46
4.3. Theory for coupled LAMs 47
4.4. Fitting examples 74
4.5. Conclusion and future work 77
4.6. References 78

Chapter 5. Simplified yet Full Theory of Microwave Three-Wave Mixing (M3WM) 87
Denis S. TIKHONOV, Wenhao SUN and Melanie SCHNELL

5.1. Introduction 87
5.2. Basic concepts 89
5.3. Semi-classical description of polarization in a molecular ensemble 108
5.4. M3WM in sequential fashion 116
5.5. M3WM driven by simultaneous pulses 129
5.6. Decoherence of the M3WM signal 133
5.7. Conclusion 139
5.8. Appendix 139
5.9. References 140

Chapter 6. A Network Approach to High-Resolution and Precision Spectroscopy 143
Attila G. CSÁSZÁR, Roland TÓBIÁS, Péter ÁRENDÁS and Tibor FURTENBACHER

6.1. Introduction 143
6.2. Measured line positions and related issues 146
6.3. Spectroscopic networks 149
6.4. MARVEL 156
6.5. Network-based design of spectroscopic experiments 164
6.6. Acknowledgments 169
6.7. References 169

Chapter 7. Using Internal Coordinates and Iterative Eigensolvers to Compute (Ro-)Vibrational Energy Levels 179
Tucker CARRINGTON JR.

7.1. Introduction 179
7.2. Deriving the kinetic energy operator 180
7.3. Basis functions 184
7.3.1. Vibrational basis functions 184
7.4. Eigensolvers 186
7.5. Using iterative methods with a product basis set 187
7.6. Using contracted bases with the Lanczos method 189
7.7. Conclusion 192
7.8. Acknowledgments 193
7.9. References 193

Chapter 8. Adiabatic and Diabatic Representations in Diatomic Molecules: A Rovibronic Context 199
Ryan P. BRADY and Sergei N. YURCHENKO

8.1. Introduction 199
8.2. The BO approximation 201
8.3. Beyond BO: NACs 205
8.4. Conditions for a strictly diabatic representation 210
8.5. Computing the AtDT 214
8.6. Conclusion 225
8.7. References 226

Chapter 9. From Ab Initio, to Variational Methods, Effective Models and High-Resolution Spectra Analyses 231
Oleg EGOROV, Andrei NIKITIN and Vladimir TYUTEREV

9.1. Introduction 231
9.2. Born–Oppenheimer approximation 232
9.3. Derivation of the KEO for the nuclear motion 244
9.4. Dipole-allowed transitions 247
9.5. Contact transformations to effective Hamiltonians 252
9.6. Application to high-resolution spectra analyses 258
9.7. References 260x High-Resolution Molecular Spectroscopy 1A

Conclusion 267
Iwona GULACZYK, Michaël REY and Ha TRAN

List of Authors 269
Index 273
Summary of Volume 1B 277