Buch, Englisch, 288 Seiten
Theory
Buch, Englisch, 288 Seiten
ISBN: 978-1-78945-255-6
Verlag: Wiley
This is the second of two volumes providing a comprehensive overview of the theoretical foundations of modern high-resolution molecular spectroscopy. They highlight the significant progress achieved in recent decades, driven largely by advances in computing power and laser technologies. These books bring together complementary chapters that explain how theoretical developments, computational methods and modeling approaches allow scientists to extract precise molecular information from complex spectra.
Key topics include the treatment of non-rigid molecules, large-amplitude motions, effective Hamiltonians and variational techniques, all of which support accurate interpretation of rotational, vibrational and rovibrational spectra in diverse molecular systems. Both books also explore emerging and specialized techniques, such as microwave three wave mixing for chiral analysis, spectroscopic networks for validating data and improved treatments of non-adiabatic effects. Finally, they emphasize the importance of collisional effects in real spectroscopic environments, presenting advanced models for line shapes, spectral broadening, shifts and line mixing based on classical, semi-classical and quantum mechanical approaches.
Autoren/Hrsg.
Fachgebiete
Weitere Infos & Material
Foreword ix
Jonathan TENNYSON
Introduction xiii
Iwona GULACZYK, Michaël REY and Ha TRAN
Chapter 1. Automated Rovibrational Configuration Interaction Calculations 1
Subhasish DAS and Guntram RAUHUT
1.1. Introduction 1
1.2. The Hamiltonian 2
1.3. VSCF/VCI calculations 5
1.4. RVCI calculations 10
1.5. Infrared intensities 19
1.6. Conclusion and outlook 24
1.7. Acknowledgments 26
1.8. References 26
Chapter 2. Efficient Numerical and Group-Theoretical Methods for Computing Spectra 31
Michaël REY
2.1. Introduction 31
2.2. Exploiting symmetry in molecular spectroscopy 32
2.2.1. Group theory for rigid and nonrigid molecules 33
2.2.2. Symmetry-adapted functions and irreducible tensor operators 35
2.3. Variational calculation 42
2.3.1. Computation of ro-vibrational energy levels by pruning the basis 42
2.3.2. Nested tensor train contracted basis functions and symmetry 45
2.4. Hamiltonian for semirigid molecules 49
2.4.1. ITO formulation of the Eckart–Watson Hamiltonian 49
2.4.2. ITO formulation of Eckart-frame Hamiltonians in curvilinear coordinates 51
2.4.3. ITO formulation of ab initio effective Hamiltonians and dipole moment operators 53
2.5. Hybrid Hamiltonian for non-rigid molecules: ITO formulation of the Hougen–Bunker–Johns formalism 55
2.6. Calculation of rotation–vibration spectra 58
2.7. References 59
Chapter 3. Isolated Line Shape Theory 65
Ha TRAN, Ngoc Hoa NGO and Piotr WCISLO
3.1. Introduction 65
3.2. Doppler broadening and the Gauss profile 67
3.3. Collisional broadening and shift and the Lorentz and Voigt profiles 68
3.3.1. Collisional broadening and shift and the Lorentz profile 68
3.3.2. The usual Voigt profile 68
3.4. Refined collisional effects and line-shape profiles 71
3.4.1. Dicke narrowing effect 71
3.4.2. The speed dependence of line broadening and shift 75
3.4.3. The Hartmann–Tran profile 78
3.4.4. The modified Hartmann–Tran profile 82
3.5. Beyond the impact appr
