Chemistry Computational chemistry is a branch of chemistry that utilizes computer simulations and mathematical modeling to study the properties and behaviors of molecular and atomic systems. It enables scientists to predict chemical reactions, molecular structures, and interactions with a high level of precision, often complementing experimental methods. This discipline employs various theoretical frameworks and algorithms, such as density functional theory and molecular dynamics, to explore complex chemical phenomena, making it an invaluable tool for research in materials science, drug design, and biochemistry.
Theoretical Foundations Quantum Mechanics Schrödinger Equation Time-independent Schrödinger Equation Application to Hydrogen Atom Solutions in Different Potentials Free Particle Finite and Infinite Potential Well Harmonic Oscillator Rigid Rotor Quantum Tunneling Approximate Numerical Methods Variational Principle Perturbation Theory Born-Oppenheimer Approximation Separation of Electronic and Nuclear Motion Application to Spectroscopy Limitations and Validity Non-Born-Oppenheimer Effects Hartree-Fock Theory Self-Consistent Field Method Slater Determinants Electron Correlation Limitations Applications in Atomic and Molecular Systems Post-Hartree-Fock Methods Møller-Plesset Perturbation Theory MP2, MP3, MP4 Levels Computational Cost vs. Accuracy Configuration Interaction Full CI vs. Truncated CI Singles and Doubles Configuration Interaction (CISD) Multi-Reference CI Coupled Cluster Theory CCSD and CCSD(T) Advantages of Coupled Cluster Methods Molecular Mechanics Force Fields Overview and Basic Components Bonded Interactions Non-bonded Interactions Van der Waals Forces Electrostatic Interactions Parametrization Techniques Specific Force Fields MM2, MM3, MMFF Applications in Small Organic Molecules AMBER Biomolecular Applications Specific Amber Variants (e.g., GAFF, ff99SB) CHARMM Protein and Nucleic Acid Simulations CHARMM Force Field Extensions GROMOS Development for Aqueous and Non-aqueous Systems Density Functional Theory (DFT) Basic Principles and Hohenberg-Kohn Theorems Local Density Approximation (LDA) Application to Homogeneous Electron Gas Limitations in Inhomogeneous Systems Generalized Gradient Approximation (GGA) Improvements Over LDA Examples of GGA Functionals (e.g., PBE, BLYP) Hybrid Functionals Incorporation of Hartree-Fock Exchange Popular Hybrid Functionals and Applications B3LYP and its Tuning Time-Dependent DFT (TDDFT) Description of Electronic Excitations Applications in Photophysics Advantages and Limitations in TDDFT Statistical Mechanics Fundamental Concepts Microstates and Macrostates Boltzmann Distribution Partition Functions Monte Carlo Simulations Random Sampling Techniques Importance Sampling Metropolis Algorithm Applications in Phase Transitions Molecular Dynamics Classical Equations of Motion Ensembles in Molecular Dynamics NVT, NPT, and Other Ensembles Time Integration Methods Verlet and Leap-frog Algorithms Simulation of Liquids, Solids, and Gases Coupling with Quantum Methods for Quantum MD