Computational Aspects for Large Chemical Systems

1.0 Introduction.- 1.1 Statement of the Problem.- 1.2 Definition of Chemical Complexity.- 1.3 On the Upper Limit of Quantum Chemical Computations.- 1.4 A General Method for Simulations of a Complex Chemical System.- 2.0 Complexity Because of the "Size" of the Largest Molecule in the System.- 2.1 Comments on Conformational Analyses for a Single Molecule.- 2.2 A New Method for Protein-Substrate Interaction Simulations..- 2.2.1 Macrodeformations.- 2.2.2 Microdeformations.- 2.3 Further Improvements for Enzymatic Reaction Simulations.- 3.0 Analyses of Chemical Bonds.- 3.1 Introduction.- 3.2 Bond Energy Analysis.- 3.3 One-Center Energies and the Molecular Orbital Valance State.- 3.4 Two-Center Bond Energy: Benzene.- 3.5 Orbital and Electron Energies.- 3.6 MOVS and Hybridization.- 3.7 Bond Energy Analysis: A "New" Formalism.- 3.8 Chemical Formulae From the Bonded Atom Pairs Analysis.- 3.9 Definition of Atoms and Molecules.- 3.10 BEA and Reaction Surface.- 3.11 BAP and Reaction Surface.- 3.12 Bond Energy Analysis and Vibrational Analysis.- 4.0 Atom-Atom Pair Potentials.- 4.1 Preliminary Comments.- 4.2 Atomic Classes for Atoms in Molecules.- 4.3 Determination of Two-Body Pair Potentials.- 4.4 Pair Potentials and Ab Initio Computations.- 4.5 Minimal Basis Set and Basis Set Superposition Error.- 4.6 The Dispersion Energy.- 4.7 Three and Many Body Corrections.- 5.0 Complexity Because of the Number of Components in the Chemical System.- 5.1 Liquid Water.- 5.2 Ion Water Clusters: Two Body Potentials.- 5.3 Ionic Solutions: Effective Two Body Potentials.- 5.4 Ionic Solutions: n-Body Correction.- 5.5 Energy Maps and Water Structure In Solutions.- 5.6 Monte Carlo Simulation of the Interaction Between Glycine and the Corresponding Zwitterion.- 5.7 Serine and the Corresponding Zwitterion.- 5.8 Enzyme-Water Interaction in Solution: A Preliminary Study on Lysozyme.- 5.9 The Water Structure in the Active Cleft of Human Carbonic Anhydrase/B.- 5.10 Contour Maps for the Molecular Fragments of DNA.- 5.11 Monte Carlo Simulations for Bases and Base-Pairs in Nucleic Acids.- 5.12 Solvation of B-DNA Double Helix at T=300 DegreesK.- 5.13 Solvation of Na+/-B-DNA at 300 DegreesK.- 5.14 Conclusion.- 6.0 References.