Molekulardynamische

Molekulardynamische is the term used in several European languages to denote molecular dynamics, a computational approach for simulating the physical movements of atoms and molecules. In practice, molecular dynamics (MD) studies follow the time evolution of a system by solving Newton's equations of motion for all particles under a chosen potential energy function. The trajectories generated provide microscopic insight into structures, conformational changes, diffusion, and thermodynamic properties.

A typical workflow includes building a model, selecting a force field, solvating the system, performing energy minimization, equilibrating at a target temperature and pressure, and running production simulations. Time steps of about 1 femtosecond are common, with total simulated times ranging from nanoseconds to microseconds or longer on modern hardware. The method relies on classical mechanics and pre-defined interaction potentials rather than on on-the-fly quantum calculations for every interaction.

Key components of molecular dynamics are the force field parameters that describe bonded interactions (bonds, angles, dihedrals) and non-bonded interactions (Lennard-Jones and electrostatics). Long-range electrostatics are often treated with methods such as Ewald sums or Particle Mesh Ewald. Simulations typically employ periodic boundary conditions to mimic bulk behavior and use ensembles such as NVE, NVT, or NPT, with thermostats and barostats to control temperature and pressure.

Applications span biomolecules (proteins, nucleic acids), membranes, materials, and liquids. MD can be combined with quantum mechanical methods (QM/MM) to treat reactive events. Limitations include the reliance on empirical force fields, the classical treatment of nuclei, sampling challenges, and the computational cost of extending simulations to biologically relevant timescales.