Path integral molecular dynamics (PIMD) is a method of incorporating
quantum mechanics into
molecular dynamics simulations using
Feynman path integral
The path integral formulation is a description in quantum mechanics that generalizes the action principle of classical mechanics. It replaces the classical notion of a single, unique classical trajectory for a system with a sum, or functional i ...
s. In PIMD, one uses the
Born–Oppenheimer approximation to separate the
wavefunction into a nuclear part and an electronic part. The nuclei are treated quantum mechanically by mapping each quantum nucleus onto a classical system of several fictitious particles connected by springs (harmonic potentials) governed by an effective Hamiltonian, which is derived from Feynman's path integral. The resulting classical system, although complex, can be solved relatively quickly. There are now a number of commonly used condensed matter computer simulation techniques that make use of the path integral formulation including Centroid Molecular Dynamics (CMD), Ring Polymer Molecular Dynamics (RPMD), and the Feynman-Kleinert Quasi-Classical Wigner (FK-QCW) method. The same techniques are also used in
path integral Monte Carlo (PIMC).
Combination with other simulation techniques
Applications
The technique has been used to calculate time correlation functions.
References
Further reading
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External links
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* {{cite journal, author=John Shumway; Matthew Gilbert , year=2008, title=Path Integral Monte Carlo Simulation, doi=10.4231/D3T43J39D , url=http://nanohub.org/resources/pimc
Molecular dynamics
Quantum chemistry
Quantum Monte Carlo