PREDICTION OF STRUCTURAL AND THERMOCHEMICAL PROPERTIES: COMPUTATIONAL STRATEGIES FOR SMALL MOLECULES TO PERIODIC SYSTEMS By Zainab H. A. Alsunaidi A DISSERTATION Submitted to Michigan State University in partial fulfillment of the requirements for the degree of Chemistry – Doctor of Philosophy 2017 ABSTRACT PREDICTION OF STRUCTURAL AND THERMOCHEMICAL PROPERTIES: COMPUTATIONAL STRATEGIES FOR SMALL MOLECULES TO PERIODIC SYSTEMS By Zainab H. A. Alsunaidi The prediction of thermochemical properties is central in chemistry and is essential in industry to predict the stability of materials and to gain understanding about properties of reactions of interest such as enthalpies of formation, activation energies and reaction enthalpies. Advances in state-of-the-art computing and algorithms as well as high-level ab initio methods have accounted for the generation of a considerable amount of thermochemical data. Today, the field of thermochemistry is largely dominated by computational methods, particularly with their low cost relative to the cost of experiment. There are many computational approaches used for the prediction of thermochemical properties. In selecting an approach, considerations about desired level of accuracy and computational efficiency need to be made. Strategies that have shown utility in the prediction of thermochemical properties with high accuracy and lower computational cost than high-level ab initio methods are ab initio composite approaches, or model chemistries, such as the correlation consistent Composite Approach (ccCA). ccCA has been shown to predict enthalpies of formation within “chemical accuracy”, which is considered to be 1 kcal mol -1, on average, for main group elements with respect to well-established experiments. In this dissertation, ccCA and the commonly used G n composite methods have been utilized to establish effective routes for the determination of structural and thermochemical properties of oxygen fluorides species and for organoselenium compounds. To assess the reliability of these approaches, enthalpies of formation were calculated and compared to experimental data. Density functionals have also been employed in these projects to examine their performance in comparison to experiments as well as to composite methods. The impact of several thermochemical approaches on the accuracy of the predicted enthalpies of formation via various computational methods has been also considered such as the traditional atomization approach and molecular reaction approaches. Additionally, in this dissertation, the reaction of a direct amination of benzene to produce aniline on the Ni(111) surface was investigated to identify possible reaction intermediates and to determine the thermodynamically preferred reaction pathways. The adsorption behaviors and energetics of all species involved in this reaction are presented. Periodic density functionals were used to consider this heterogeneous catalytic process. Because DFT is based on the uniform electron gas model, which in principle resembles the band theory of metallic systems, DFT is particularly good at modeling metallic systems and thus well suited for the study of heterogeneous catalysts at the molecular level. Copyright by ZAINAB H. A. ALSUNAIDI 2017 This dissertation is dedicated to my husband Uthman and children Riadh, Sahar, and Yousef. Thank you for always believing in me. v ACKNOWLEDGMENT I would first like to praise and thank Allah for all the countless blessings and for giving me the strength and courage to complete this dissertation. The faith in his support, glory, and mercy has always held me strong. Upon completion, I would like to acknowledge many people who have been supportive during my graduate career. First, I would like to thank my research advisor Professor Angela K. Wilson for continuous support and patience during my PhD study at both the University of North Texas and Michigan State University. Her mentorship, guidance, motivation, and leadership have contributed to my growth as an independent scientist. I am very grateful to her for encouraging me to get publications and to present at conferences. Her words, advice, and actions have all granted me an incredible academic experience at the U.S. I acknowledge financial support from the University of Dammam in Saudi Arabia. I believe that this scholarship has contributed successfully to my personal and academic development. It also gave me the opportunity to meet and learn from outstanding scientists from around the world. Without their financial support, none of this would have been possible. I acknowledge Professor Thomas Cundari for collaboration on the work presented in Chapter 5 and for his support and enthusiastic sharing of knowledge. I thank my committee members here at Michigan State University Professor James “Ned” Jackson, Professor Gary Blanchard, and Professor Katharine Hunt for their time and suggestions. I also thank my former committee members at the university of North Texas Professor Thomas Cundari, Professor Paul Marshall, and Professor Mohammad Omary for their time and suggestions during my qualifying exams. vi Thank you to my amazing colleagues in the Wilson group, past and present, for their continuous sharing of knowledge and techniques. Thank you to Dr. Jiaqi Wang and Michael Jones for support and helpful conversation. I thank Dr. Kameron Jorgensen, who introduced me to ab initio composite methods, Dr. Charlie Peterson for fruitful discussion and for help with my solid state calculations, and Dr. George Schoendorff and Dr. Inga Ulusoy for thoughtful and interesting discussions. I thank Dr. Deborah Penchoff, for her friendship, many enriching conversations, and help in managing challenges and stress along the way. I thank my friends who have been there for me during my Ph.D. work. All of my friends in Denton have helped me to keep focus and maintain balance through these hectic years. I thank them for constant cheering and for making our stay in Denton a pleasant experience. The support from my friends in Saudi Arabia has always been substantial for my success. Their words, prayers, and encouragement always have been like fuel to continue and to succeed. I am especially grateful to my immediate family for their love, prayers, words and encouragements that have been sources of strength and inspiration. I express my greatest gratitude to my parents, Sajedah and Dr. Husain, for their endless support, prayers, and love, and who made me what I am today. I am very grateful to my mother- and father-in-law, Khaledah and Riadh, for their support, love, and encouragement. My deepest gratitude goes to all my siblings for consistent motivation, support, love, prayers and always believing in me. Finally, I am endlessly grateful to the love of my life, my husband, Uthman Alhumaidan, for his patience, understanding, and keeping me calm through all of my stressful challenges. Your wisdom, genius, kindness, love, and trust have contributed the most in my success. No such words can describe my gratitude and appreciation. You have been always there for me either to celebrate a little achievement or to overcome obstacles. I cannot remember any time that you vii were disappointed in me even with all of my frustration and absence. Thank you for reminding me and keeping me involved in my kids’ childhood. Without your support, none of this would have been possible. To my precious gems Riadh, Sahar, and Yousef, thank you for being such responsible, supportive, and respectful kids. Thank you for always bringing joy and love to my life. You are my heroes and my everything. viii TABLE OF CONTENTS LIST OF TABLES ............................................................................................................................... xii LIST OF FIGURES ............................................................................................................................. xv LIST OF SCHEMES .......................................................................................................................... xvii CHAPTER 1 INTRODUCTION ........................................................................................................... 1 CHAPTER 2 THEORETICAL BACKGROUND ................................................................................. 6 2.1 The Schrödinger Equation .................................................................................................... 6 2.1.1 Born-Oppenheimer Approximation ............................................................................................ 8 2.1.2 Slater Determinant ....................................................................................................................... 9 2.1.3 Variational Principle ................................................................................................................. 10 2.2 Ab initio Methods ................................................................................................................ 11 2.2.1 Hartree-Fock Approximation .................................................................................................... 11 2.2.2 Post-HF Methods....................................................................................................................... 13 2.2.2.1 Configuration Interaction ...................................................................................... 14 2.2.2.2 Perturbation Theory .............................................................................................. 15 2.2.2.3 Coupled Cluster