Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Official government website icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

icon-https

Secure .gov websites use HTTPS
A lock ( Lock Locked padlock icon )or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases NIH: National Institute of Diabetes and Digestive and Kidney Diseases

  next up previous contents index  Xplor-NIH home Documentation

Next: Finite Difference Approximation Up: Temperature Control Previous: Langevin Dynamics

Temperature Coupling

This option is turned on by TCOUpling. This method was described by Berendsen et al. (1984). It is essentially a Langevin-type method with zero random forces and a scaled friction coefficient. The friction coefficient is computed by the program from the equation
\begin{displaymath}
b_i=b_i^I (T_o/T -1)
\end{displaymath} (11.7)

where $b_i^I$ is given by the FBETa atom property. Note that FBETa is by default zero; i.e., FBETa has to be specified in order to use TCOUpling. The target temperature $T_o$ is specified by the TBATh parameter. $T=\sum_i m_i {dx_i \over dt}^2 / ( {n_{deg} k_B} ) $ is the temperature of the system at the particular step where $n_{deg}$ is the number of degrees of freedom of the system. Thus, a positive fricition coefficient is applied if the system is too hot, a negative friction coefficient is applied if the system is too cold, and no friction is applied if $T$ matches $T_o$.



Xplor-NIH 2025-03-21
  • Privacy Policy
  • Freedom of Information Act
  • Accessibility
  • Disclaimers
  • Copyright
  • Vulnerability Disclosure Policy
  • U.S. Department of Health and Human Services
  • National Institutes of Health