Boltzmann distribution¶
This module initialises particle velocities from a Boltzmann distribution.
The velocity distribution per degree of freedom is a Gaussian with mean \(\mu_{v} = 0\) and width \(\sigma_{v} = \sqrt{\frac{kT}{m}}\),
\[f\left(v\right) = \sqrt{\frac{m}{2\pi kT}} \exp\left(\frac{-mv^2}{2 kT}\right)\]
To account for the finite size of the system, the velocities are shifted,
\[\vec{v}_\text{shifted} \equiv \vec{v} - \vec{V}_\text{cm}\]
to yield a centre of mass velocity of zero.
- class halmd.mdsim.velocities.boltzmann(args)¶
Construct boltzmann module.
- Parameters:
args (table) – keyword arguments
args.particle – instance of
halmd.mdsim.particle
args.temperature (number) – temperature of distribution
- set()¶
Initialise particle velocities from Boltzmann distribution.
- temperature¶
Temperature of the distribution in reduced units. The value can be changed by assignment.