Chien Siu-Hung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract (English) / Abstract (Chinese) / Acknowledgements / Table of Contents / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- The Gaussian-2 Method / Chapter 1.2 --- The Gaussian-3 Method / Chapter 1.3 --- The G3 Method with Reduced Moller-Plesset Order and Basis Set / Chapter 1.4 --- Calculated Thermochemical Data / Chapter 1.5 --- Remark on the Location of Transition State / Chapter 1.6 --- Scope of the Thesis / Chapter 1.7 --- References / Chapter Chapter 2 --- "Energetics and Structures of the Carbonyl Chloride Radical, Oxalyl Chloride, and Their Cations" --- p.6 / Chapter 2.1 --- Introduction / Chapter 2.2 --- Computational Methods / Chapter 2.3 --- Results and Discussion / Chapter 2.3.1 --- Carbonyl Chloride and Its Cation / Chapter 2.3.2 --- The anti and syn Conformers of Oxalyl Chloride and Oxalyl Chloride Cation / Chapter 3.3.3 --- The anti and gauche Conformers of (ClCO) 2 and the TS Linking Them / Chapter 2.4 --- Conclusions / Chapter 2.5 --- Publication Note / Chapter 2.6 --- References / Chapter Chapter 3 --- "An Isomeric Study of N5, N5+，and N5- : A Gaussian-3 Investigation" --- p.17 / Chapter 3.1 --- Introduction / Chapter 3.2 --- Computational Methods / Chapter 3.3 --- Results and Discussion / Chapter 3.3.1 --- "The N5 Isomers """ / Chapter 3.3.2 --- The N5+ Isomers / Chapter 3.3.3 --- The N5- Isomers / Chapter 3.3.4 --- Comparison of the G3 and G3(MP2) Results / Chapter 3.4 --- Conclusions / Chapter 3.5 --- Publication Note / Chapter 3.6 --- References / Chapter Chapter 4 --- Thermochemistry of Hydrochlorofluorosilanes : An Ab Initio Gaussian-3 Study --- p.28 / Chapter 4.1 --- Introduction / Chapter 4.2 --- Computational Methods / Chapter 4.3 --- Results and Discussion / Chapter 4.3.1 --- Heats of Formation for Neutral HCFSis / Chapter 4.3.2 --- Ionization Energies / Chapter 4.3.3 --- Electron Affinities / Chapter 4.3.4 --- Proton Affinities / Chapter 4.3.5 --- Acidities / Chapter 4.3.6 --- G3 versus G3(MP2) / Chapter 4.4 --- Conclusions / Chapter 4.5 --- Publication Note / Chapter 4.6 --- References / Chapter Chapter 5 --- A Gaussian-3 Study of the Photodissociation Channels of Thiirane --- p.48 / Chapter 5.1 --- Introduction / Chapter 5.2 --- Computational Methods / Chapter 5.3 --- Results and Discussion / Chapter 5.3.1 --- The Heats of Reactions / Chapter 5.3.2 --- The Dissociation Channels Taking Place at the Ground State / Chapter 5.3.3 --- The Dissociation Channels Taking Place at Excited States / Chapter 5.4 --- Conclusions / Chapter 5.5 --- References / Chapter Chapter 6 --- A Gaussian-3 Study of the VUV Photoionization and Photodissociation of Chloropropylene Oxide --- p.59 / Chapter 6.1 --- Introduction / Chapter 6.2 --- Computational Methods / Chapter 6.3 --- Results and Discussion / Chapter 6.3.1 --- Ionization Energy / Chapter 6.3.2 --- Dissociation Channels / Chapter 6.4 --- Conclusions / Chapter 6.5 --- Publication Note / Chapter 6.6 --- References / Chapter Chapter 7 --- Conclusions --- p.69 / Appendix A The Gaussian-n (n=l-3) Theoretical Models --- p.71 / Chapter A.1 --- The G1 and G2 Theories / Chapter A.2 --- The G3 Theory / Chapter A.3 --- The G3(MP2) Theory / "Appendix B Calculation of Enthalpy at 298 K,H298" --- p.74

Li Chi-Lun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iii / Table of Contents --- p.iv / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Remark on the Location of Transition Structures --- p.1 / Chapter 1.2 --- Scope of the Thesis --- p.1 / Chapter 1.3 --- References --- p.2 / Chapter Chapter 2 --- "A Gaussian-3 Study on the Photodissociation of Phenylacetylene and Formation of 1,3,5-Hexatriyne" --- p.5 / Chapter 2.1 --- Introduction --- p.6 / Chapter 2.2 --- Computational Method --- p.7 / Chapter 2.3 --- Results and Discussion --- p.8 / Chapter 2.3.1 --- Phenylacetylene → Acetylene + Benzyne --- p.8 / Chapter 2.3.2 --- "Phenylacetylene → Acetylene + (Z)-3 -Hexene- 1,5-diyne" --- p.9 / Chapter 2.3.3 --- "(Z)-3-Hexene-l,5-diyne / (E)-3 -Hexene-1,5-diyne → 1,3,5-Hexatriyne and Molecular Hydrogen" --- p.9 / Chapter 2.3.4 --- Evaluation of Thermochemical Data --- p.10 / Chapter 2.3.5 --- Evaluation of Ion Energetics Data --- p.10 / Chapter 2.4 --- Conclusions --- p.10 / Chapter 2.5 --- References --- p.11 / Chapter Chapter 3 --- A Gaussian-3 Study of the Photoionization and Dissociative Photoionization Channels of Cyanoethylene --- p.21 / Chapter 3.1 --- Introduction --- p.22 / Chapter 3.2 --- Computational Method --- p.22 / Chapter 3.3 --- Results and Discussion --- p.23 / Chapter 3.3.1 --- Bond Cleavage Reactions --- p.23 / Chapter 3.3.2 --- Dissociation Channels Involving Transition Structures --- p.25 / Chapter 3.4 --- Conclusions --- p.25 / Chapter 3.5 --- References --- p.26 / Chapter Chapter 4 --- "A Gaussian´ؤ2 Study of Structures, Energetics, and Reactions of C2H3S- Anions" --- p.34 / Chapter 4.1 --- Introduction --- p.35 / Chapter 4.2 --- Computational Method --- p.35 / Chapter 4.3 --- Results and Discussion --- p.36 / Chapter 4.3.1 --- Thioformylmethyl Anion --- p.37 / Chapter 4.3.2 --- Thioacetyl Anion --- p.37 / Chapter 4.3.3 --- Cyclic C2H3S- Ions --- p.37 / Chapter 4.3.4 --- CH2SCH- --- p.38 / Chapter 4.3.5 --- 2-Thiovinyl Anion --- p.38 / Chapter 4.3.6 --- 1-Thiovinyl Anion --- p.39 / Chapter 4.3.7 --- Intramolecular Rearrangements of 1- --- p.39 / Chapter 4.3.8 --- Intramolecular Rearrangements of Cyclic C2H3S- ions and 1´ؤThiovinyl Anion --- p.39 / Chapter 4.4 --- Conclusions --- p.40 / Chapter 4.5 --- References --- p.40 / Chapter Chapter 5 --- "Theoretical Studies of Transition Metal Complexes: Bond Energies for Fe+-D, Fe+-H2O, and Fe+-CO" --- p.51 / Chapter 5.1 --- Introduction --- p.52 / Chapter 5.2 --- Computational Method --- p.53 / Chapter 5.3 --- Results and Discussion --- p.54 / Chapter 5.3.1 --- Fe+-D --- p.54 / Chapter 5.3.2 --- Fe+-CO --- p.54 / Chapter 5.3.3 --- Fe+-H2O --- p.55 / Chapter 5.4 --- Conclusions --- p.56 / Chapter 5.5 --- References --- p.57 / Chapter Chapter 6 --- Ab Initio Study of the Charge-Delocalized and -Localized Form of the Rhodizonate Dianion --- p.61 / Chapter 6.1 --- Introduction --- p.62 / Chapter 6.2 --- Computational Method --- p.63 / Chapter 6.3 --- Results and Discussion --- p.64 / Chapter 6.3.1 --- Charge-Localized C6062- --- p.64 / Chapter 6.3.2 --- Charge-Delocalized C6062- --- p.64 / Chapter 6.4 --- Conclusions --- p.65 / Chapter 6.5 --- References --- p.66 / Chapter Chapter 7 --- "Franck-Condon Factor Simulated Spectra of the Cations of cis-2-Butene,trans-2-Butene, Isobutene, cis-Dichloroethene, and trans-Dichloroethene" --- p.71 / Chapter 7.1 --- Introduction --- p.72 / Chapter 7.2 --- Computational Method --- p.72 / Chapter 7.3 --- Results and Discussion --- p.73 / Chapter 7.3.1 --- cis-2-Butene Cation --- p.73 / Chapter 7.3.2 --- trans-2-Butene Cation --- p.74 / Chapter 7.3.3 --- cis-Dichloroethene Cation --- p.75 / Chapter 7.3.4 --- trans-Dichloroethene Cation --- p.76 / Chapter 7.3.5 --- Isobutene --- p.76 / Chapter 7.4 --- Conclusions --- p.77 / Chapter 7.5 --- References --- p.77 / Chapter Chapter 8 --- Conclusions --- p.88 / Appendix A --- p.89 / Appendix B --- p.91 / Appendix C --- p.92

Lam Chow Shing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references. / Abstracts in English and Chinese. / Thesis Examination Committee --- p.i / Abstract --- p.ii / Acknowledgements --- p.iv / Table of Contents --- p.v / List of Tables --- p.vii / List of Figures --- p.viii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- The Gaussian-3 Method --- p.1 / Chapter 1.2 --- The G3 Method with Reduced MΦller- Plesset Order and Basis Set --- p.2 / Chapter 1.3 --- Density Functional Theory (DFT) --- p.3 / Chapter 1.4 --- Calculation of Thermodynamical Data --- p.3 / Chapter 1.5 --- Remark on the Location of Transition Structures --- p.3 / Chapter 1.6 --- Natural Bond Orbital (NBO) Analysis --- p.4 / Chapter 1.7 --- Scope of the Thesis --- p.4 / Chapter 1.8 --- References --- p.5 / Chapter Chapter 2 --- Theoretical Study of Tri-s-triazine and Its Derivatives --- p.7 / Chapter 2.1 --- Introduction --- p.7 / Chapter 2.2 --- Methods of Calculation --- p.9 / Chapter 2.3 --- Results and Discussion --- p.9 / Chapter 2.3.1. --- Property of Tri-s-triazine --- p.9 / Chapter 2.3.2. --- Substituent Effects on the Properties of the Tri-s-triazine Parent Molecule --- p.10 / Chapter 2.3.3. --- Heats of Formation of Derivatives of Tri-s-triazine --- p.20 / Chapter 2.4 --- Conclusion --- p.22 / Chapter 2.5 --- References --- p.22 / Chapter Chapter 3 --- A Gaussian-3 Study of the Dissociative Photoionization of Acetone --- p.25 / Chapter 3.1 --- Introduction --- p.25 / Chapter 3.2 --- Methods of Calculation --- p.26 / Chapter 3.3 --- Results and Discussion --- p.26 / Chapter 3.3.1. --- "Formation of m/z = 42 (CH2CO+.),43 (CH3CO+) Ions" --- p.31 / Chapter 3.3.2. --- Formation of m/z = 43 (c-CH2CHO+) and m/z = 15 (CH3+) Ions --- p.32 / Chapter 3.3.3. --- Formation of m/z = 57 (CH3COCH2+) Ions --- p.37 / Chapter 3.3.4. --- Formation of m/z = 39 (C3H3+) Ions --- p.38 / Chapter 3.4 --- Conclusion --- p.40 / Chapter 3.5 --- Publication Note --- p.40 / Chapter 3.6 --- References --- p.40 / Chapter Chapter 4 --- "A G3(MP2) Study of the C3H60+. Isomers Fragmented from l,4-Dioxane+" --- p.42 / Chapter 4.1 --- Introduction --- p.42 / Chapter 4.2 --- Methods of Calculation --- p.43 / Chapter 4.3 --- Results and Discussion --- p.44 / Chapter 4.3.1. --- "Formation of C3H60+. Isomers 1 and 2 via Fragmentation of 1,4-Dioxane+" --- p.44 / Chapter 4.3.2. --- Reaction with Acetonitrile --- p.55 / Chapter 4.3.3. --- Reaction with Formaldehyde --- p.57 / Chapter 4.3.4. --- Reaction with Ethylene --- p.61 / Chapter 4.3.5. --- Reaction with Propene --- p.63 / Chapter 4.4 --- Conclusion --- p.67 / Chapter 4.5 --- Publication Note --- p.68 / Chapter 4.6 --- References --- p.68 / Chapter Chapter 5 --- A Computational Study of the Photodissociation Channels of Chloroiodomethane --- p.71 / Chapter 5.1 --- Introduction --- p.71 / Chapter 5.2 --- Methods of Calculation --- p.73 / Chapter 5.3 --- Results and Discussion --- p.74 / Chapter 5.3.1 --- CH2C1 + I(2P1/2) and CH2C1 + I(2P3/2) Channels --- p.77 / Chapter 5.3.2 --- "CH2I + C1(2P3/2,1/2) Channel" --- p.78 / Chapter 5.3.3 --- CHI + HC1 Channel --- p.80 / Chapter 5.3.4 --- CH2 + IC1 Channel --- p.81 / Chapter 5.4 --- Conclusion --- p.82 / Chapter 5.5 --- Publication Note --- p.83 / Chapter 5.6 --- References --- p.83 / Chapter Chapter 6 --- Conclusion --- p.86 / Appendix A --- p.87 / Appendix B --- p.89

Lau Kai-Chung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract / Acknowledgements / Table of Contents / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- The Gaussian-2 Method / Chapter 1.2 --- The G2 Method with Reduced M φller-Plesset Order and Basis Set / Chapter 1.3 --- The Gaussian-3 Method / Chapter 1.4 --- Our Modified G2 Methods / Chapter 1.5 --- Calculation of Thermodynamical Data / Chapter 1.6 --- Scope of the Thesis / Chapter 1.7 --- Remark on the Location of Transition Structures / Chapter 1.8 --- References / Chapter Chapter 2 --- A Gaussian-2 Study of the [C2H5O-] Potential Energy Surface and the Fragmentation Pathways of the Ethoxide Anion --- p.7 / Chapter 2.1 --- Introduction / Chapter 2.2 --- Theoretical Methods / Chapter 2.3 --- Results and Discussion / Chapter 2.3.1 --- Stable Isomers and TSs for the [C2H50-] Anions / Chapter 2.3.2 --- Fragmentation Pathways of the Ethoxide Anion (1-) / Chapter 2.4 --- Conclusions / Chapter 2.5 --- Publication Note / Chapter 2.6 --- References / Chapter Chapter 3 --- A Gaussian-2 Study of Isomeric C2H2N and C2H2N+ --- p.20 / Chapter 3.1 --- Introduction / Chapter 3.2 --- Theoretical Methods / Chapter 3.3 --- Results and Discussion / Chapter 3.3.1 --- The C2H2N and C2H2N+ Isomers / Chapter 3.3.2 --- The Cyanomethyl Radical (1) and Cation (1+) / Chapter 3.3.3 --- The Isocyanomethyl Radical (2) and Cation (2+) / Chapter 3.3.4 --- The lH-Azirinyl Radical (5) and Cation (5+) / Chapter 3.3.5 --- Other C2H2N and C2H2N+ Isomers / Chapter 3.3.6 --- The Unidentified C2H2N Isomer Formed in N + CH=CH2 / Chapter 3.4 --- Conclusions / Chapter 3.5 --- Publication Note / Chapter 3.6 --- References / Chapter Chapter 4 --- A Gaussian-2 Study of the Photoionization and Dissociative Photoionization Channels of Ethylene Oxide --- p.35 / Chapter 4.1 --- Introduction / Chapter 4.2 --- Theoretical Methods / Chapter 4.3 --- Results and Discussion / Chapter 4.3.1 --- Bond Cleavage Reactions / Chapter 4.3.2 --- Dissociation Channels Involving Transition Structure(s) / Chapter 4.4 --- Conclusions / Chapter 4.5 --- Publication Note / Chapter 4.6 --- References / Chapter Chapter 5 --- A Gaussian-2 Study of the Photoionization and Dissociative Photoionization Channels of Propylene Oxide --- p.47 / Chapter 5.1 --- Introduction / Chapter 5.2 --- Theoretical Methods / Chapter 5.3 --- Results and Discussion / Chapter 5.3.1 --- Bond Cleavage Reactions / Chapter 5.3.2 --- Dissociation Channels Involving Transition Structure(s) / Chapter 5.4 --- Conclusions / Chapter 5.5 --- Publication Note / Chapter 5.6 --- References / Chapter Chapter 6 --- A Gaussian-3 Study of the Thermochemistry of Chlorofluoromethanes (CFnCl4-n) and Their Cations (CFnCl4_n+)， n =0-4 --- p.61 / Chapter 6.1 --- Introduction / Chapter 6.2 --- Theoretical Methods / Chapter 6.3 --- Results and Discussions / Chapter 6.3.1 --- Heats of Formation of Chlorofluoromethanes and Their Cations / Chapter 6.3.2 --- Ionization Energies of Chlorofluoromethanes / Chapter 6.3.3 --- Proton Affinities of Chlorofluoromethanes / Chapter 6.4 --- Conclusions / Chapter 6.5 --- Publication Note / Chapter 6.6 --- References / Chapter Chapter 7 --- "A Gaussian-2 and Gaussian-3 Study of the Energetics and Structures of Cl2On and Cl2On+, n = 1，4, 6，and7" --- p.69 / Chapter 7.1 --- Introduction / Chapter 7.2 --- Theoretical Methods / Chapter 7.3 --- Results and Discussion / Chapter 7.3.1 --- Cl20 and Cl20+ / Chapter 7.3.2 --- Cl204 and Cl204+ / Chapter 7.3.3 --- Cl206 and Cl206+ / Chapter 7.3.4 --- Cl207 and Cl207+ / Chapter 7.4 --- Conclusions / Chapter 7.5 --- Publication Note / Chapter 7.6 --- References / Chapter Chapter 8 --- Conclusions --- p.81 / Chapter Appendix A --- The Gaussian-n (n = 1 - 3) Theoretical Models --- p.82 / Chapter A.1 --- The G1 and G2 theories / Chapter A.2 --- The G2(MP2) theory / Chapter A.3 --- "The G2(MP2,SVP) theory" / Chapter A.4 --- The G3 theory / Chapter Appendix B --- "Calculation of Enthalpy at 298 K, H298" --- p.86

Law Chi-Kin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iii / Table of Contents --- p.iv / List of Tables --- p.vi / List of Figures --- p.viii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- The Gaussian´ؤ3 Method --- p.1 / Chapter 1.2 --- The G3 Method with Reduced Mφller-Plesset Order and Basis Set --- p.2 / Chapter 1.3 --- The Gaussian-3X Method --- p.2 / Chapter 1.4 --- Calculation of Thermodynamical Data --- p.3 / Chapter 1.5 --- Remark on the Location of Equilibrium and Transition Structures --- p.3 / Chapter 1.6 --- Natural Bond Orbital (NBO) Analysis --- p.4 / Chapter 1.7 --- Scope of the Thesis --- p.4 / Chapter 1.8 --- References --- p.5 / Chapter Chapter 2 --- Gaussian´ؤ3 Heats of Formation for (CH)6 Isomers --- p.6 / Chapter 2.1 --- Introduction --- p.6 / Chapter 2.2 --- Methods of Calculation and Results --- p.7 / Chapter 2.3 --- Discussion --- p.9 / Chapter 2.4 --- Conclusion --- p.11 / Chapter 2.5 --- Publication Note --- p.12 / Chapter 2.6 --- References --- p.12 / Chapter Chapter 3 --- A Gaussian-3 Investigation of N7 Isomers --- p.14 / Chapter 3.1 --- Introduction --- p.14 / Chapter 3.2 --- Computational Method and Results --- p.16 / Chapter 3.3 --- Discussion --- p.16 / Chapter 3.4 --- Conclusion --- p.24 / Chapter 3.5 --- Publication Note --- p.24 / Chapter 3.6 --- References --- p.24 / Chapter Chapter 4 --- A Gaussian-3 Study of N7+ and N7- Isomers --- p.27 / Chapter 4.1 --- Introduction --- p.27 / Chapter 4.2 --- Computational Method and Results --- p.29 / Chapter 4.3 --- Discussion --- p.30 / Chapter 4.3.1 --- The N7+ isomers --- p.30 / Chapter 4.3.2 --- The N7- isomers --- p.37 / Chapter 4.4 --- Conclusion --- p.41 / Chapter 4.5 --- Publication Note --- p.41 / Chapter 4.6 --- References --- p.41 / Chapter Chapter 5 --- "Thermochemistry of Chlorine Fluorides ClFn, n = 1-7, and Their Singly Charged Cations and Anions: A Gaussian-3 and Gaussian-3X Study" --- p.45 / Chapter 5.1 --- Introduction --- p.45 / Chapter 5.2 --- Methods of Calculations --- p.47 / Chapter 5.3 --- Results and Discussion --- p.48 / Chapter 5.3.1 --- Comparison of the G3 and G3X methods --- p.48 / Chapter 5.3.2 --- Assessments of the experimental results --- p.54 / Chapter 5.3.3 --- "Bond dissociation energies of ClFn, ClFn+, and ClFn-" --- p.57 / Chapter 5.3.4 --- Summary of the thermochemical data --- p.58 / Chapter 5.4 --- Conclusion --- p.59 / Chapter 5.5 --- Publication Note --- p.60 / Chapter 5.6 --- References --- p.60 / Chapter Chapter 6 --- A Gaussian-3 Study of the Photoionization and Dissociative Photoionization Channels of Dimethyl Sulfide --- p.63 / Chapter 6.1 --- Introduction --- p.63 / Chapter 6.2 --- Methods of Calculations --- p.64 / Chapter 6.3 --- Results and Discussion --- p.64 / Chapter 6.3.1 --- Bond cleavage reactions --- p.67 / Chapter 6.3.2 --- Dissociation channels involving transition structures --- p.68 / Chapter 6.4 --- Conclusion --- p.70 / Chapter 6.5 --- Publication Note --- p.70 / Chapter 6.6 --- References --- p.70 / Chapter Chapter 7 --- "Theoretical Study of the Electronic Structures of Carbon and Silicon Nanotubes, Carbon and Silicon Nanowires" --- p.72 / Chapter 7.1 --- Introduction --- p.72 / Chapter 7.2 --- Models and Computational Methods --- p.74 / Chapter 7.3 --- Results and Discussion --- p.75 / Chapter 7.4 --- Conclusion --- p.87 / Chapter 7.5 --- Publication Note --- p.87 / Chapter 7.6 --- References --- p.87 / Chapter Chapter 8 --- Conclusion --- p.90 / Appendix A --- p.91 / Appendix B

Cheng Mei-Fun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iii / Table of Contents --- p.iv / List of Tables --- p.vi / List of Figures --- p.viii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- The Gaussian-3 Method --- p.1 / Chapter 1.2 --- The G3 Method with Reduced Mφller-Plesset Order and Basis Set --- p.2 / Chapter 1.3 --- Density Functional Theory (DFT) --- p.3 / Chapter 1.4 --- Calculation of Thermodynamical Data --- p.3 / Chapter 1.5 --- Remark on the Location of Transition Structures --- p.3 / Chapter 1.6 --- Natural Bond Orbital (NBO) Analysis --- p.4 / Chapter 1.7 --- Scope of the Thesis --- p.4 / Chapter 1.8 --- References --- p.5 / Chapter Chapter 2 --- Heats of Formation for the Azine Series: A Gaussian-3 Study --- p.7 / Chapter 2.1 --- Introduction --- p.7 / Chapter 2.2 --- Methods of Calculation and Results --- p.8 / Chapter 2.3 --- Discussion --- p.8 / Chapter 2.4 --- Conclusion --- p.9 / Chapter 2.5 --- Publication Note --- p.10 / Chapter 2.6 --- References --- p.10 / Chapter Chapter 3 --- Heats of Formation for Some Boron Hydrides: A Gaussian-3 Study --- p.16 / Chapter 3.1 --- Introduction --- p.16 / Chapter 3.2 --- Methods of Calculation and Results --- p.18 / Chapter 3.3 --- Discussion --- p.19 / Chapter 3.4 --- Conclusion --- p.21 / Chapter 3.5 --- Publication Note --- p.21 / Chapter 3.6 --- References --- p.21 / Chapter Chapter 4 --- Structural and Energetics Studies of Tri- and Tetra-tert-butylmethane --- p.30 / Chapter 4.1 --- Introduction --- p.30 / Chapter 4.2 --- Methods of Calculation and Results --- p.32 / Chapter 4.3 --- Discussion --- p.34 / Chapter 4.3.1 --- Mono-tert-butylmethane --- p.34 / Chapter 4.3.2 --- Di-tert-butylmethane --- p.35 / Chapter 4.3.3 --- Tri-tert-butylmethane --- p.37 / Chapter 4.3.4 --- Tetra-tert-butylmethane --- p.38 / Chapter 4.4 --- Conclusion --- p.39 / Chapter 4.5 --- Publication Note --- p.40 / Chapter 4.6 --- References --- p.40 / Chapter Chapter 5 --- A Computational Study of the Diels-Alder Reactions Involving Acenes: Reactivity and Aromaticity --- p.49 / Chapter 5.1 --- Introduction --- p.49 / Chapter 5.2 --- Methods of Calculation and Results --- p.50 / Chapter 5.3 --- Discussion --- p.51 / Chapter 5.4 --- Conclusion --- p.53 / Chapter 5.5 --- Publication Note --- p.53 / Chapter 5.6 --- References --- p.53 / Chapter Chapter 6 --- A Computational Study of the Charge- Delocalized and Charge-Localized Forms of the Croconate and Rhodizonate Dianions --- p.65 / Chapter 6.1 --- Introduction --- p.65 / Chapter 6.2 --- Methods of Calculation and Results --- p.67 / Chapter 6.3 --- Discussion --- p.68 / Chapter 6.3.1 --- Charge-Localized Forms of C5052- (C2v) and C6O6 2-(C2v) --- p.68 / Chapter 6.3.2 --- Charge-Delocalized Forms of C5052- (D5h) and C6062- (D6h) --- p.71 / Chapter 6.4 --- Conclusion --- p.72 / Chapter 6.5 --- Publication Note --- p.73 / Chapter 6.6 --- References --- p.74 / Chapter Chapter 7 --- Conclusion --- p.89 / Appendix A --- p.90 / Appendix B --- p.92

Lau Kai-Chi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iii / Table of Contents --- p.iv / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- The Gaussian´ؤ3 Method --- p.1 / Chapter 1.2 --- The G3 Method with Reduced MΦ ller-Plesset Order and Basis Set --- p.2 / Chapter 1.3 --- The Gaussian-3X Method --- p.2 / Chapter 1.4 --- The Modified G2 Method --- p.3 / Chapter 1.5 --- Calculation of Thermodynamical Data --- p.3 / Chapter 1.6 --- Remark on the Location of Transition Structures --- p.4 / Chapter 1.7 --- Scope of the Thesis --- p.4 / Chapter 1.8 --- References --- p.4 / Chapter Chapter 2 --- "A Gaussian-2 and Gaussian-3 Study of Alkoxide Anion Decompositions. I. H2 and CH4 Eliminations of the Methoxide, Ethoxide, i-Propoxide, and t-Butoxide Anions" --- p.6 / Chapter 2.1 --- Introduction --- p.6 / Chapter 2.2 --- Methods of Calcuations --- p.7 / Chapter 2.3 --- Results and Discussion --- p.8 / Chapter 2.3.1 --- Nature of ion-neutral complex --- p.8 / Chapter 2.3.2 --- Initial bond cleavage of alkoxide anions --- p.9 / Chapter 2.3.3 --- Dissociation of alkoxide anions --- p.10 / Chapter 2.4 --- Conclusions --- p.23 / Chapter 2.5 --- Publication Note --- p.25 / Chapter 2.6 --- References --- p.25 / Chapter Chapter 3 --- A Gaussian-2 and Gaussian-3 Study of Alkoxide Anion Decompositions. II. Alkane Eliminations of (CH3)2(C2H5)CO- and (i-Pr)(C2H5)2CO- --- p.28 / Chapter 3.1 --- Introduction --- p.28 / Chapter 3.2 --- Methods of Calculations --- p.29 / Chapter 3.3 --- Results and Discussion --- p.29 / Chapter 3.3.1 --- Initial bond cleavage of alkoxide anions --- p.30 / Chapter 3.3.2 --- Dissociation of alkoxde anions --- p.31 / Chapter 3.3.3 --- General dissociation mechanism of alkoxide anions --- p.35 / Chapter 3.4 --- Conclusions --- p.37 / Chapter 3.5 --- References --- p.37 / Chapter Chapter 4 --- A Gaussian-3 Study of the Photoionization and Dissociative Photoionization Channels of Dimethyl Disulfide --- p.40 / Chapter 4.1 --- Introduction --- p.40 / Chapter 4.2 --- Methods of Calculations --- p.41 / Chapter 4.3 --- Results and Discussion --- p.41 / Chapter 4.3.1 --- Bond cleavage reactions --- p.44 / Chapter 4.3.2 --- Dissociation channels involving transition structures --- p.45 / Chapter 4.4 --- Conclusions --- p.48 / Chapter 4.5 --- References --- p.48 / Chapter Chapter 5 --- A Gaussian´ؤ3 Study of the Photodissociation Channels of Propylene Sulfide --- p.50 / Chapter 5.1 --- Introduction --- p.50 / Chapter 5.2 --- Methods of Calculations --- p.51 / Chapter 5.3 --- Results and Discussion --- p.51 / Chapter 5.3.1 --- The dissociation channels involving transition structures --- p.53 / Chapter 5.3.2 --- The dissociations of sulfur atom --- p.56 / Chapter 5.4 --- Conclusions --- p.58 / Chapter 5.5 --- References --- p.59 / Chapter Chapter 6 --- Thermochemistry of Phosphorus Fluorides: A Gaussian´ؤ3 and Gaussian´ؤ3X Study --- p.60 / Chapter 6.1 --- Introduction --- p.60 / Chapter 6.2 --- Methods of Calculations --- p.62 / Chapter 6.3 --- Results and Discussion --- p.62 / Chapter 6.3.1 --- Comparison of the G3 and G3X methods --- p.62 / Chapter 6.3.2 --- Assessments of the experimental results --- p.65 / Chapter 6.4 --- Conclusions --- p.71 / Chapter 6.5 --- References --- p.71 / Chapter Chapter 7 --- Conclusions --- p.74 / Appendix A --- p.75 / Appendix B --- p.78

Thesis (Ph. D.)--University of North Texas, May, 2009. / Title from title page display. Includes bibliographical references.

Employing correlation consistent basis sets coupled with electronic structure methods has enabled accurate predictions of chemical properties for second- and third-row main group and transition metal molecular species. For third-row (Ga-Kr) molecules, the performance of the correlation consistent basis sets (cc-pVnZ, n=D, T, Q, 5) for computing energetic (e.g., atomization energies, ionization energies, electron and proton affinities) and structural properties using the ab initio coupled cluster method including single, double, and quasiperturbative triple excitations [CCSD(T)] and the B3LYP density functional method was examined. The impact of relativistic corrections on these molecular properties was determined utilizing the Douglas-Kroll (cc-pVnZ-DK) and pseudopotential (cc-pVnZ-PP) forms of the correlation consistent basis sets. This work was extended to the characterization of molecular properties of novel chemically bonded krypton species, including HKrCl, FKrCF3, FKrSiF3, FKrGeF3, FKrCCF, and FKrCCKrF, and provided the first evidence of krypton bonding to germanium and the first di-krypton system. For second-row (Al-Ar) species, the construction of the core-valence correlation consistent basis sets, cc-pCVnZ was reexamined, and a revised series, cc-pCV(n+d)Z, was developed as a complement to the augmented tight-d valence series, cc-pV(n+d)Z. Benchmark calculations were performed to show the utility of these new sets for second-row species. Finally, the correlation consistent basis sets were used to study the structural and spectroscopic properties of Au(CO)Cl, providing conclusive evidence that luminescence in the solid-state can be attributed to oligomeric species rather than to the monomer.

Conjuntos de funções de base Gaussianos são desenvolvidos para os átomos da primeira fila dos metais de transição Sc - Zn. Esses conjuntos de base foram construídos por meio do método da Coordenada Geradora Hartree-Fock (GCHF - Generator Coordinate Hartre-Fock) baseado em uma expansão polinomial de grau 3 para discretizar as equações Griffin-Wheeler-Hartree-Fock. Neste procedimento, a maneira na qual as equações são discretizadas está baseada em uma malha de pontos flexíveis não igualmente espaçada para cada uma das simetrias orbitais requeridas para descrever os átomos estudados, a diferença do método GCHF original é que a malha é igualmente espaçada para todas as simetrias. Inicialmente, foi gerado um conjunto de base balanceado consistindo de 23s17p13d funções gaussianas primitivas. A partir deste, um conjunto padrão de qualidade 7Z na valência foi construído e, posteriormente, enriquecido com grupos de funções de polarização e gerando assim:pGCHF - 7Z - 2f 1g, pGCHF - 7Z - 3f 2g e pGCHF - 7Z - 3f 2g1h. Energias atômicas Hartree-Fock para os dois estados eletrônicos de menor energia, para os átomos do Sc - Zn, foram calculadas com nossos conjuntos e comparadas com valores da energia numérica. Os resultados apresentaram um erro máximo de 1.02 mHartree, demostrando a capacidade desta expansão polinomial no desenvolvimento de conjuntos de base acurados para átomos dos metais de transição (MT) 3d. Cálculos em nível da Teoria do Funcional da Densidade (DFT - Density Functional Theory), utilizando nove diferentes funcionais, foram realizados com nossos conjuntos de base. A energia eletrônica total e propriedades incluíndo: geometrias otimizadas, cumprimentos de ligação e, frequências vibracionais, foram examinadas para um conjunto de sistemas moleculares (hidretos, dicloretos, dímeros, trímeros e óxidos de metais de transição). Os resultados são comparados com valores teóricos obtidos com conjuntos de base cc-pVnZ (n= Q ou 5) e com valores experimentais, quando disponiveís na literatura. Os resultados mostram que os valores de energia total cc-pV5Z, podem ser atingidos com nossos conjuntos de base com um menor número de funções de polarização. Outros cálculos moleculares dão resultados aproximados com valores experimentais e valores de referência DFT/cc-pV5Z. O ponto mais importante para ser mencionado é que os conjuntos de base da coordenada geradora requerem somente uma pequena fração de tempo computacional para alcançar a convergência, quando comparados com cálculos DFT/cc-pVQZ e DFT/cc-pV5Z. / Gaussian basis set functions have been constructed for the atoms of the first row of the transition metals from Sc to Zn. These basis sets were built by means of the Generator Coordinate Hartree-Fock (GCHF) method based on a polynomial expansion of degree 3 for the discretization of the Grifin-Wheler-Hartree-Fock equations. In this procedure, the equations were discretized through a mesh which is not equally spaced for each one of the orbital symmetries required to describe the atoms studied in this work, differently from the original method, in which the mesh is equally spaced for all symmetries. At first, it was generated a minimal basis set consisting of 23s17p13d primitive functions. Starting with this pattern set was construted a set of 7Z quality in the valence and then, this one was enriched with polarization functions classified as: 2f1g, 3f2g y 3f2g1h, which originated 3 sets of basis functions namely: pGCHF-7Z-2f1g, pGCHF-7Z-3f2g y pGCHF-7Z-3f2g1h. Hartree-Fock energies for the atoms Sc-Zn were calculated with our basis sets, for the two electronic states with the lowest energy and compared with values of numerical energy. The maximum error presented for the results was 1.02mH, showing the ability of this polynomial expansion to create accurate basis sets for atoms of third-rows transition metals. Density Functional Theory (DFT) calculations using a set of nine functionals were realized with our basis sets. The total electronic energy and properties such as: optimized geometries, bond distances and vibrational frequencies were calculated for a set of molecules (hydrides, dichlorides, dimers, trimmers and oxides). The obtained values were compared with theoretical values obtained with calculations using the basis set cc-pVnZ and with some experimental values found in the literature. The outcomes showed that reference values of the total electronic can be reproduced by ours basis sets, although ours have a less degree of polarization. Other molecular calculations yield results very close to experimental values and reference theorical values calculated with DFT/cc-pV5Z. The most important point to be mentioned here is that our generator coordinate basis sets require only a tiny fraction of the computational time when compared to DFT/cc-pV5Z calculations.