From b14fb8d61069d3f1a73c602194207ba107a0b0ef Mon Sep 17 00:00:00 2001 From: athomps <athomps@f3b2605a-c512-4ea7-a41b-209d697bcdaa> Date: Mon, 4 Nov 2013 02:30:55 +0000 Subject: [PATCH] Qualified the GJF description git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@10923 f3b2605a-c512-4ea7-a41b-209d697bcdaa --- doc/fix_langevin.html | 10 ++++++---- doc/fix_langevin.txt | 10 ++++++---- 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/doc/fix_langevin.html b/doc/fix_langevin.html index eeedfd5f6d..7f5b7d5717 100644 --- a/doc/fix_langevin.html +++ b/doc/fix_langevin.html @@ -244,10 +244,12 @@ effective random force is composed of the average of two random forces representing half-contributions from the previous and current time intervals. This discretization has been shown to be consistent with the underlying physical model of Langevin dynamics and produces the -correct statistical distribution of energy for large timesteps, up to -the numerical stability limit. A typical simulation with flexible -hydrogen-carbon covalent bonds can be run with a timestep of 3 fs, -instead of 1 fs with the standard Langevin method. +correct Boltzmann distribution of positions for large timesteps, +up to the numerical stability limit. Because the discretized momenta +generated by the time integration scheme are not exactly conjugate +to the positions, the kinetic energy distribution is systematically +lower than the Boltzmann distribution by an amount that +grows with the timestep. </P> <HR> diff --git a/doc/fix_langevin.txt b/doc/fix_langevin.txt index 817a157c2b..4218564a4c 100644 --- a/doc/fix_langevin.txt +++ b/doc/fix_langevin.txt @@ -232,10 +232,12 @@ effective random force is composed of the average of two random forces representing half-contributions from the previous and current time intervals. This discretization has been shown to be consistent with the underlying physical model of Langevin dynamics and produces the -correct statistical distribution of energy for large timesteps, up to -the numerical stability limit. A typical simulation with flexible -hydrogen-carbon covalent bonds can be run with a timestep of 3 fs, -instead of 1 fs with the standard Langevin method. +correct Boltzmann distribution of positions for large timesteps, +up to the numerical stability limit. Because the discretized momenta +generated by the time integration scheme are not exactly conjugate +to the positions, the kinetic energy distribution is systematically +lower than the Boltzmann distribution by an amount that +grows with the timestep. :line -- GitLab