Advances in Quantum Chemistry (eBook)

Applications of Theoretical Methods to Atmospheric Science

Erkki J. Brandas, John R. Sabin (Herausgeber)

eBook Download: EPUB

2011 | 1. Auflage
500 Seiten
Elsevier Science (Verlag)
978-0-08-087805-8 (ISBN)

Infos

Advances in Quantum Chemistry presents surveys of current developments in this rapidly developing field that falls between the historically established areas of mathematics, physics, chemistry, and biology. With invited reviews written by leading international researchers, each presenting new results, it provides a single vehicle for following progress in this interdisciplinary area.
Theoretical methods have dramatically extended the reach and grasp of atmospheric scientists. This edition of Advances in Quantum Chemistry collects a broad range of articles that provide reports from the leading edge of this interaction. The chemical systems span the range from atoms to clusters to droplets. Electronic structure calculations are used to uncover the details of the breakdown and removal of emissions from the atmosphere and the simultaneous development of air pollution including ozone and particles. The anomalous enrichment of heavy isotopes in atmospheric ozone is discussed using RRKM theory, and a number of techniques are presented for calculating the effect of isotopic substitution on the absorption spectra of atmospheric molecules.

* Publishes articles, invited reviews and proceedings of major international conferences and workshops
* Written by leading international researchers in quantum and theoretical chemistry
* Highlights important interdisciplinary developments

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Approx.500 pagesApprox.500 pages

Inhalt

Front cover 1
Applications of Theoretical Methods to Atmospheric Science 4
Copyright page 5
Contents 6
Contributors 12
Chapter 1. Applications of Theoretical Methods to Atmospheric Science 18
Acknowledgements 20
References 21
Chapter 2. Mass-Independent Oxygen Isotope Fractionation in Selected Systems. Mechanistic Considerations 22
1. Introduction 23
2. The MIF in Ozone Formation 27
3. Quantum Dynamical Computations 29
4. Individually Studied Ratios of Isotopomeric Reaction Rate Constants 30
5. Rate Constant Ratios and Enrichments for Other Reactions 32
6. Oxygen Isotopic Fractionation for CO + OH -> CO2 + H
Acknowledgements 35
References 35
Chapter 3. An Important Well Studied Atmospheric Reaction, O (1D)+H2 38
1. Introduction 39
2. Characterization of the O (1D) + H2 Reaction 40
3. Potential Energy Surfaces 42
4. Dynamical Studies 43
5. Results and Comparison with Experiment 45
6. Final Remarks and Conclusions 56
Acknowledgements 56
References 56
Chapter 4. Gaseous Elemental Mercury in the Ambient Atmosphere: Review of the Application of Theoretical Calculations and Experimental Studies for Determination of Reaction Coefficients and Mechanisms with Halogens and Other Reactants 60
1. Introduction 61
2. Kinetic and Product Experiments 62
3. Theoretical Evaluation of Kinetic Data 67
4. Perspectives 70
Acknowledgements 70
References 71
Chapter 5. Photolysis of Long-Lived Predissociative Molecules as a Source of Mass-Independent Isotope Fractionation: The Example of SO2 74
1. Introduction 75
2. Absorption Spectra for SO2 Isotopologues 76
3. Photolysis of SO2 Isotopologues in a Low O2 Atmosphere 81
4. Photolysis of SO2 in the Modern Atmosphere 85
5. Improvements to Spectra and Additional Sources of S-MIF 87
6. Conclusions and Broader Implications 90
Acknowledgements 90
References 91
Chapter 6. A New Model of Low Resolution Absorption Cross Section 92
1. Introduction and Motivations 92
2. Improved Model of Low Resolution Absorption Cross Section (XS) for Diatomic Molecules 95
3. Quantum Correction to the Low Resolution Absorption Cross Section of Diatomic Molecules 97
4. The Absorption Cross Section of Cl2 Molecule 101
5. A 3D Version of the Model and Its Application to Triatomic Molecules 106
6. Conclusions and Perspectives 113
Acknowledgements 114
Appendix A. A Polynomial Version of Formula (12') 114
Appendix B. A Polynomial Version of Formula (27') 115
Appendix C. The Temperature Dependence of the Absorption Cross Section 116
References 117
Chapter 7. Isotope Effects in Photodissociation: Chemical Reaction Dynamics and Implications for Atmospheres 118
1. Introduction 119
2. Electronic Structure Calculations 120
3. Construction of the Time-Independent Hamiltonian Operator 125
4. Time-Independent Methods 126
5. Time-Dependent Methods 128
6. Examples of Photodissociation 132
7. Perspective 145
Acknowledgements 146
References 146
Chapter 8. Atmospheric Photolysis of Sulfuric Acid 154
1. Introduction 155
2. Vibrational Transitions 158
3. Electronic Transitions 166
4. Atmospheric Simulations 170
5. Conclusion 172
Acknowledgements 173
References 173
Chapter 9. Computational Studies of the Thermochemistry of the Atmospheric Iodine Reservoirs HOI and IONO2 176
1. Introduction 177
2. Methodology and Results 178
3. Discussion 182
4. Conclusions 190
Acknowledgements 190
References 191
Chapter 10. Theoretical Investigation of Atmospheric Oxidation of Biogenic Hydrocarbons: A Critical Review 194
1. Introduction 194
2. Theoretical Approaches in Atmospheric Hydrocarbon Oxidation Research 195
3. Theoretical Investigation of Biogenic Hydrocarbon Oxidation 200
4. Conclusions and Future Research 224
Acknowledgements 226
References 226
Chapter 11. Computational Study of the Reaction of n-Bromopropane with OH Radicals and Cl Atoms 232
1. Introduction 233
2. Computational Methods 236
3. Results and Discussion 237
4. Atmospheric Implications 258
5. Conclusion 259
Acknowledgements 260
References 260
Chapter 12. Atmospheric Reactions of Oxygenated Volatile Organic Compounds+OH Radicals: Role of Hydrogen-Bonded Intermediates and Transition States 262
1. Introduction 263
2. Kinetics 264
3. Energies 268
4. Aliphatic Alcohols 269
5. Aldehydes 273
6. Ketones 275
7. Carboxylic Acids 281
8. Multifunctional Oxygenated Volatile Organic Compounds 283
9. Concluding Remarks 285
References 287
Chapter 13. Theoretical and Experimental Studies of the Gas-Phase Cl-Atom Initiated Reactions of Benzene and Toluene 292
1. Introduction 293
2. Methods 294
3. Results and Discussions 296
4. Conclusions 309
References 311
Chapter 14. Tropospheric Chemistry of Aromatic Compounds Emitted from Anthropogenic Sources 314
1. Introduction 315
2. Reactions 315
3. Summary: Areas for Future Work 326
References 326
Chapter 15. Elementary Processes in Atmospheric Chemistry: Quantum Studies of Intermolecular Dimer Formation and Intramolecular Dynamics 328
1. Introduction 329
2. Major Atmospheric Components and Their Dimers 330
3. Aspects of Interactions Involving Minor Atmospheric Components: H2O and H2S 336
4. Peroxides and Persulfides 341
5. Concluding Remarks and Perspectives 345
Acknowledgements 345
References 345
Chapter 16. The Study of Dynamically Averaged Vibrational Spectroscopy of Atmospherically Relevant Clusters Using Ab Initio Molecular Dynamics in Conjunction with Quantum Wavepackets 350
1. Introduction 351
2. Computational Methods for Soft Vibrational Mode Clusters 352
3. Cluster Dynamics Simulations using ADMP and QWAIMD 359
4. Conclusions 365
Acknowledgements 365
References 365
Chapter 17. From Molecules to Droplets 372
1. Introduction 373
2. Energy Functional and Hamiltonians 375
3. The Introduction of the Multiconfigurational Self-Consistent Wave Function 383
4. Derivation of Response Equations for Quantum-Classical Systems 386
5. Brief Overview of Results 398
6. Conclusion 399
Acknowledgement 400
References 400
Chapter 18. Theoretical Studies of the Dissociation of Sulfuric Acid and Nitric Acid at Model Aqueous Surfaces 404
1. Introduction 405
2. Methodology 406
3. First Acid Dissociation of Sulfuric Acid 410
4. Acid Dissociation of Nitric Acid 414
5. Concluding Remarks 418
Acknowledgements 419
References 419
Chapter 19. Investigating Atmospheric Sulfuric Acid-Water-Ammonia Particle Formation Using Quantum Chemistry 424
1. Introduction 424
2. Theoretical Methods for Free Energy Calculations 428
3. Applications of Quantum Chemistry to Atmospheric Nucleation Phenomena 432
4. Challenges 440
5. Conclusions 441
Acknowledgements 442
References 442
Chapter 20. The Impact of Molecular Interactions on Atmospheric Aerosol Radiative Forcing 446
1. Introduction 446
2. Atmospheric Physics 451
3. Background on Nucleation Theories 455
4. Dynamical Nucleation Theory 457
5. Why Accurate Chemical Physics is Important to Nucleation 461
6. Summary and Future Directions 462
Acknowledgements 463
References 463
Chapter 21. Computational Quantum Chemistry: A New Approach to Atmospheric Nucleation 466
1. Introduction 467
2. Nucleation Theory 471
3. Why Should We Apply the Quantum Theory to Atmospheric Problems? 472
4. Quantum Methods 473
5. Application of Quantum Methods to Atmospheric Species 474
6. Concluding Remarks 492
Acknowledgements 492
References 492
Subject Index 496

Textauszug

Chapter 1

Applications of Theoretical Methods to Atmospheric Science

Matthew S. Johnson*; Michael E. Goodsite**,***    * Copenhagen Center for Atmospheric Research, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
** Department of Physics and Chemistry, University of Southern Denmark, Campusvej 55, DK-5230 Odense, Denmark
*** Department of Atmospheric Environment, National Environmental Research Institute, Aarhus University, Frederiksborgvej 399, P.O. Box 358, DK-4000 Roskilde, Denmark

Publisher Summary

Theoretical techniques have revolutionized the study of chemistry. Due to the parallel development of theoretical methods and computing power, quantum chemistry has become fast and flexible, often yielding detailed insight into chemical processes that cannot be obtained in the laboratory. The earliest report of combining quantum chemistry with the atmosphere deals with the excitation of nitrogen and oxygen molecules as the primary event in the photo-excitation of the atmosphere. Models of atmospheric chemistry have grown with the abilities of computers and the demands of simulating climate change. One example is the simulation of isotopic fractionation in the photolysis of nitrous oxide isotopologues using time-dependent wave-packet propagation. Quantum chemistry provides data that improves understanding of chemical kinetics. The data is further used as input for parameterizing transport and deposition models or chemical reaction schemes in models of various other atmospheric processes. Theoretical techniques are tested through comparison to laboratory measurements and atmospheric observations, and then further applied towards predicting mechanisms and reaction rates which are currently unknown.

Theoretical chemistry involves explaining chemical phenomenon using natural laws. The primary tool of theoretical chemistry is quantum chemistry, and the field may be divided into electronic structure calculations, reaction dynamics and statistical mechanics. These three play a role in addressing an issue of primary concern: understanding photochemical reaction rates at the various conditions found in the atmosphere. Atmospheric science includes both atmospheric chemistry and atmospheric physics, meteorology, climatology and the study of extraterrestrial atmospheres.

The chemical side of atmospheric science has grown considerably in the past generation because it is now recognized that chemistry is at the heart of a wide range of atmospheric phenomenon including acid rain, ozone depletion, air pollution, the atmospheric transport, conversion and deposition of pollutants such as mercury and perfluorinated species, greenhouse gas budgets, determining the impact of biofuels and biogenic emissions, and cloud formation. This list is incomplete, but the point is that atmospheric chemistry provides insight into issues that are of central importance to modern society. At the same time theoretical techniques have revolutionized the study of chemistry. Due to the parallel development of theoretical methods and computing power, quantum chemistry has become fast and flexible, often yielding detailed insight into chemical processes that cannot be obtained in the laboratory.

One may debate the relative importance of theory and experiment. The late Gert Due Billing [1] said that if the theory and the experiment disagree, check the experiment, and if they agree, check the theory. Atmospheric science offers a third alternative: check the atmosphere. The atmosphere is rich hunting ground for theorists looking for interesting systems to study. The atmosphere is an engine for generating problems that matter, examples including ozone depletion, air pollution and the nucleation of new particles. In addition the proliferation of ground-based monitoring stations, balloons and satellites has provided a large database of measurements that can be used to inspire and anchor theoretical results.

The earliest report we know of combining quantum chemistry with the atmosphere deals with the excitation of nitrogen and oxygen molecules as the primary event in the photo-excitation of the atmosphere. Krauss et al. reported theoretical calculations of the electronic properties of the molecules required for the prediction of optical emissions from normal and disturbed atmospheres, including the analysis of the electronic structure of excited states of nitrogen [2].

In 1984 Krauss and Stevens described tests and applications of the effective potential method used to gain knowledge of the electronic structure of the molecules in order to analyze the accuracy of the experimentally deduced dissociation energies of refractory metal salts [3]. They used the development of ab initio theoretical methods for the calculation of potential energy surfaces, which further allowed the direct computation of certain rate constants. Transition state theory was also utilized for this computation of some rate constants. However, as discussed by Krauss and Stevens, as of the mid 1980's computational techniques were not yet readily applied to atmospheric science. Computing power and theoretical methods since these seminal reports have been greatly advanced.

The anomalous enrichment of 17O and 18O in stratospheric ozone provides a good example of the interplay of laboratory experiments, field studies and theory. The effect was first observed in the Thiemens laboratory in 1983 [4] and then in the stratosphere by Mauersberger [5]. The first truly successful explanation of the underlying mechanism did not appear for nearly two decades in a series of articles by Rudy Marcus and coworkers [6–9], a discussion which is extended in this issue. The unique distribution of oxygen isotopes in ozone has proved to be a useful tracer for diverse atmospheric phenomena, including the exposure of CO2 to excited oxygen atoms in the stratosphere [10], the productivity of the biosphere [11] and the origin of nitrate found in polar ice [12].

Models of atmospheric chemistry have grown with the abilities of computers and the demands of simulating climate change. One example is the simulation of isotopic fractionation in the photolysis of nitrous oxide isotopologues using time-dependent wavepacket propagation [13]. The isotope-dependent absorption cross sections were used in a three dimensional global circulation model to calculate the isotopic fractionation occurring in stratospheric photolysis. The back flux of isotopically enriched N2O from the stratosphere to the troposphere could explain the observed distribution of N2O in the troposphere, reducing uncertainties in the budget of this key greenhouse gas [14]. The study was unique in proceeding directly from wavepacket propagation simulations to atmospheric modeling, the results of which could be directly and favorably compared with data from field studies of the distributions of the isotopomers and isotopologues of N2O. The theory and the atmosphere agreed, necessitating laboratory experiments which largely confirmed the theoretical studies [15]. Time-independent models have also been applied to the problem [16].

As writing was completed for this Special Issue in 2007, the articles testify to the growth and vitality of the field due to refinements of modeling and theories, advancements in computational science, and collaboration across scientific disciplines.

The roles and opportunities for the theoretical chemist as part of an atmospheric science investigative team have become both more defined and diverse. Since Krauss and Stevens [3], many of the topics they raised have been used, and continue to need to be used to advance our understanding of the chemistry of the atmosphere. For example, theoretical methods are used to predict and verify theories of the mechanistic pathways for the photooxidation of mercury (Ariya et al., this edition). The paper shows how heats of reaction are calculated by various methods, results which are then used to rule out reaction schemes.

Quantum chemistry provides data that improves understanding of chemical kinetics. The data is further used as input for parameterizing transport and deposition models or chemical reaction schemes in models of various other atmospheric processes. As documented in many of the articles in this special edition, theoretical techniques are tested through comparison to laboratory measurements and atmospheric observations, and then further applied towards predicting mechanisms and reaction rates which are currently unknown.

One of the key uncertainties in climate models is determining the radiative impact of clouds, and there is particular interest in understanding the chemistry of clouds: particle nucleation, particle growth and heterogeneous reactivity. We have organized the issue, roughly, according to the size of the systems considered, starting with three-atom systems such as ozone and O (1D) + H2 and proceeding to particle nucleation and the consideration of molecules within droplets.

It is our intention that this special edition serve as a useful catalyst and inspiration, to give the readers an idea of the state of the art and its utility in applications of theoretical methods to atmospheric science and we encourage further work in the areas specified by the authors in their contributions. All promise to have a global impact on science and the environment, and perhaps peace [17].

ACKNOWLEDGEMENTS

We are overwhelmed by the variety and quality of the articles that have come forward...

Produkt-Details

• Erscheint lt. Verlag: 6.9.2011
• Mitarbeit: Gast Herausgeber: Michael M.E. Goodsite, Matthew S. Johnson
• Sprache: englisch
• Themenwelt: Sachbuch/Ratgeber
• Themenwelt: Naturwissenschaften ► Biologie
• Themenwelt: Naturwissenschaften ► Chemie ► Physikalische Chemie
• Themenwelt: Naturwissenschaften ► Physik / Astronomie ► Atom- / Kern- / Molekularphysik
• Themenwelt: Technik
• ISBN-10: 0-08-087805-9 / 0080878059
• ISBN-13: 978-0-08-087805-8 / 9780080878058