fix nvt/manifold/rattle command

Syntax

fix ID group-ID nvt/manifold/rattle tol maxit manifold manifold-args keyword value ...
  • ID, group-ID are documented in fix command
  • nvt/manifold/rattle = style name of this fix command
  • tol = tolerance to which Newton iteration must converge
  • maxit = maximum number of iterations to perform
  • manifold = name of the manifold
  • manifold-args = parameters for the manifold
  • one or more keyword/value pairs may be appended
keyword = temp or tchain or every
  temp values = Tstart Tstop Tdamp
    Tstart, Tstop = external temperature at start/end of run
    Tdamp = temperature damping parameter (time units)
  tchain value = N
    N = length of thermostat chain (1 = single thermostat)
  every value = N
    N = print info about iteration every N steps. N = 0 means no output

Examples

fix 1 all nvt/manifold/rattle 1e-4 10 cylinder 3.0 temp 1.0 1.0 10.0

Description

This fix combines the RATTLE-based (Andersen) time integrator of fix nve/manifold/rattle (Paquay) with a Nose-Hoover-chain thermostat to sample the canonical ensemble of particles constrained to a curved surface (manifold). This sampling does suffer from discretization bias of O(dt). For a list of currently supported manifolds and their parameters, see manifolds


Restart, fix_modify, output, run start/stop, minimize info

No information about this fix is written to binary restart files. None of the fix_modify options are relevant to this fix. No global or per-atom quantities are stored by this fix for access by various output commands. No parameter of this fix can be used with the start/stop keywords of the run command. This fix is not invoked during energy minimization.


Restrictions

This fix is part of the USER-MANIFOLD package. It is only enabled if LAMMPS was built with that package. See the Making LAMMPS section for more info.

Only use this with min_style hftn or min_style quickmin. If not, the constraints will not be satisfied very well at all. A warning is generated if the min_style is incompatible but no error.