Quantum theory Mathematical models 74 Hamiltonians 16 Computer simulation 14 Molecular dynamics 12 Approximation theory 10 Eigenvalues and eigenfunctions 10 Probability density function 10 Algorithms 8 Correlation methods 8 Ground state 8 Integral equations 8 Matrix algebra 8 Molecular structure 8 Numerical methods 8 Photochemical reactions 8 Random processes 8 Brownian movement 6 Calculations 6 Diffusion 6 Electron transitions 6 Electrons 6 Fermions 6 Functions 6 Irreversibility 6 Phase transitions 6 Photons 6 Activation energy 4 Brownian motion 4 Chaos theory 4