In an ab initio MD simulation, the total energy of the system is calculated at each time step using density functional theory (DFT) or another method of quantum chemistry.
AIMD permits chemical bond breaking and forming events to occur and accounts for electronic polarization effect.
[3] Therefore, Ab initio MD simulations can be used to study a wide range of phenomena, including the structural, thermodynamic, and dynamic properties of materials and chemical reactions.
The software is a parallelized plane wave / pseudopotential implementation of density functional theory, particularly designed for ab initio molecular dynamics.
[4] The Car–Parrinello method is a type of molecular dynamics, usually employing periodic boundary conditions, planewave basis sets, and density functional theory, proposed by Roberto Car and Michele Parrinello in 1985 while working at SISSA,[1] who were subsequently awarded the Dirac Medal by ICTP in 2009.
This small fictitious mass in turn requires that the equations of motion are integrated using a smaller time step than the one (1–10 fs) commonly used in Born–Oppenheimer molecular dynamics.
CPMD uses fictitious dynamics[6] to keep the electrons close to the ground state, preventing the need for a costly self-consistent iterative minimization at each time step.
Any increase in the fictitious electron mass resulting in energy transfer would cause the system to leave the ground-state BOMD surface.