CSVR thermostat: Difference between revisions

Revision as of 08:18, 9 September 2023

One popular strategy to control temperature in NVT MD is to rescale atomic velocities at a certain predefined frequency by some factor in such a way that the total kinetic energy of the system ( $E_{kin}$ ) is equal to the average kinetic energy corresponding to given temperature ( $\bar{E}_{kin} = \frac{3}{2}(N -1)k_B T$ where $N$ is the number of atoms). Such a method, however, suffers from several issues. First of all, the ensemble generated is not strictly canonical. Also, the trajectories generated via this naive rescaling method often suffer from flying ice-cube problem where kinetic energy vibrational degrees of freedom is transferred into translations and/or rotations, violating thus equipartition principle.

An elaborated approach based on the velocity rescaling has been proposed by Bussi et al.

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	One popular strategy to control temperature in NVT MD is to rescale atomic velocities at a certain predefined frequency by some factor in such a way that the total kinetic energy is equal to the average kinetic energy corresponding to given temperature. Such a method, however, suffers from several issues. First of all, the ensemble generated is not strictly canonical. Also, the trajectories generated via this naive rescaling method often suffer from flying ice-cube problem where kinetic energy vibrational degrees of freedom is transferred into translations and/or rotations, violating thus equipartition principle.		One popular strategy to control temperature in NVT MD is to rescale atomic velocities at a certain predefined frequency by some factor in such a way that the total kinetic energy of the system (<math>E_{kin}</math>) is equal to the average kinetic energy corresponding to given temperature (<math>\bar{E}_{kin} = \frac{3}{2}(N -1)k_B T</math> where <math>N</math> is the number of atoms). Such a method, however, suffers from several issues. First of all, the ensemble generated is not strictly canonical. Also, the trajectories generated via this naive rescaling method often suffer from flying ice-cube problem where kinetic energy vibrational degrees of freedom is transferred into translations and/or rotations, violating thus equipartition principle.

	An elaborated approach based on the velocity rescaling has been proposed by Bussi et al.		An elaborated approach based on the velocity rescaling has been proposed by Bussi et al.