Improved Partial Charge Models in Siliceous Zeolites for the Simulation of Adsorption and Identification of Catalytic Sites

..................................................................................................................................................... iii Acknowledgements .................................................................................................................................... iv List of Tables ........................................................................................................................................... xiii List of Figures ............................................................................................................................................. x Chapter 1: Introduction ............................................................................................................................... 1 1.1: Density Functional Theory ............................................................................................................. 1 1.1.1: Schrödinger Equation .................................................................................................................. 1 1.1.2: Hohenberg – Kohn Theorem ....................................................................................................... 5 1.1.3: Kohn Sham .................................................................................................................................. 7 1.1.4: LDA’s, GGA’s, Meta GGA’s, Hybrids and Dispersions ............................................................ 9 1.2: Partial Charge Methods ................................................................................................................ 15 1.2.1: Semi-Empirical Techniques ....................................................................................................... 15 1.2.2: Ab Initio Techniques .................................................................................................................. 17 1.3: Sampling Thermodynamic Properties with Monte Carlo ............................................................. 20 1.4: Zeolites, a Brief Introduction ........................................................................................................ 24 Chapter 2: Predicting Partial Charges in Siliceous Zeolites ..................................................................... 27 2.1: Introduction .................................................................................................................................. 27 2.2: Methods ....................................................................................................................................... 31 2.2.1: Simulation ................................................................................................................................. 31 2.2.2: Experimental ............................................................................................................................. 33 2.3: Results and Discussion ................................................................................................................ 34 2.3.1: Comparing Charge Mythologies ............................................................................................... 34 2.3.2: The Relationship Between Acidic/Catalytic Sites and Partial Atomic Charges ....................... 36 2.3.3: The Effect of Compression on Partial Atomic Charges ........................................................... 44