NVT ensemble: Difference between revisions
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[[:Category: NVT ensemble]] | [[:Category: NVT ensemble]] | ||
== NVT ensemble == | == NVT ensemble == | ||
The NVT ensemble is a statistical ensemble that is used to study material properties under the conditions of a | The NVT ensemble is a statistical ensemble that is used to study material properties under the conditions of a | ||
constant particle number N, constant volume V and a temperature fluctuating around an equilibrium value T. | constant particle number N, constant volume V and a temperature fluctuating around an equilibrium value T. | ||
This page describes to sample the NVT ensemble from a molecular dynamics run. | |||
== Instructions for setting up a NVT ensemble == | == Instructions for setting up a NVT ensemble == | ||
There are 4 possibilities to simulate the NVT ensemble. The stochastic [[Andersen thermostat]] or [[Langevin thermostat]], | There are 4 possibilities to simulate the NVT ensemble. The stochastic [[Andersen thermostat]] or [[Langevin thermostat]], | ||
the deterministic [[Nose-Hoover thermostat]] or [[MDALGO#MDALGO.3D13:_Multiple_Anderson_thermostats]] can be used. | the deterministic [[Nose-Hoover thermostat]] or [[MDALGO#MDALGO.3D13:_Multiple_Anderson_thermostats|Multiple Anderson thermostats]] can be used. | ||
{|class="wikitable" style="margin:aut | {|class="wikitable" style="margin:aut | ||
! NVT ensemble !! Andersen !! Langevin !! Nose-Hoover !! Multiple Andersen | ! NVT ensemble !! Andersen !! Langevin !! Nose-Hoover !! Multiple Andersen | ||
|- | |- | ||
|MDALGO || 1 || 3 || 2 || 13 | |MDALGO || 1 || 3 || 2 || 13 | ||
|- {{TAG|PSUBSYS} | |- {{TAG|PSUBSYS} | ||
| additional tags || {{TAG|ANDERSEN_PROB}} || {{TAG|LANGEVIN_GAMMA}} || {{TAG|SMASS}} || {{TAG|NSUBSYS}}, {{TAG|TSUBSYS}}, {{TAG|PSUBSYS}} | | additional tags || {{TAG|ANDERSEN_PROB}} || {{TAG|LANGEVIN_GAMMA}} || {{TAG|SMASS}} || {{TAG|NSUBSYS}}, {{TAG|TSUBSYS}}, {{TAG|PSUBSYS}} | ||
|} | |} | ||
The user is not allowed to set ISF>2 because then the volume of the simulation would be allowed to change | The user is not allowed to set ISF>2 because then the volume of the simulation would be allowed to change | ||
and the simulation would not result in a NVT ensemble. | and the simulation would not result in a NVT ensemble. Setting ISIF=0 will speed up the calculation because the stress | ||
tensor is not computed. | |||
Revision as of 12:54, 19 July 2022
Category: NVT ensemble == NVT ensemble == The NVT ensemble is a statistical ensemble that is used to study material properties under the conditions of a constant particle number N, constant volume V and a temperature fluctuating around an equilibrium value T. This page describes to sample the NVT ensemble from a molecular dynamics run. == Instructions for setting up a NVT ensemble == There are 4 possibilities to simulate the NVT ensemble. The stochastic Andersen thermostat or Langevin thermostat, the deterministic Nose-Hoover thermostat or Multiple Anderson thermostats can be used.
| NVT ensemble | Andersen | Langevin | Nose-Hoover | Multiple Andersen |
|---|---|---|---|---|
| MDALGO | 1 | 3 | 2 | 13 |
| additional tags | ANDERSEN_PROB | LANGEVIN_GAMMA | SMASS | NSUBSYS, TSUBSYS, PSUBSYS |
The user is not allowed to set ISF>2 because then the volume of the simulation would be allowed to change and the simulation would not result in a NVT ensemble. Setting ISIF=0 will speed up the calculation because the stress tensor is not computed.