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# LANGEVIN GAMMA L

**LANGEVIN_GAMMA_L** = [Real]

Default: **LANGEVIN_GAMMA_L** = 0

Description: **LANGEVIN_GAMMA_L** specifies the friction coefficient (in ps^{-1}) for lattice degrees-of-freedom in case of Parrinello-Rahman dynamics (in case VASP was compiled with -Dtbdyn).

When running *NpT* simulations with a Langevin thermostat^{[1]} (MDALGO=3), using the method of Parrinello and Rahman,^{[2]}^{[3]} the friction coefficient for lattice degrees-of-freedom have to be specified (in ps^{-1}) by means of the **LANGEVIN_GAMMA_L**-tag.
A fictitious mass for the lattice degrees-of-freedom has to be assigned using the PMASS-tag.

The friction coefficients γ for the atomic degrees-of-freedom are specified using the LANGEVIN_GAMMA-tag.

## Related Tags and Sections

## References

- ↑ M. P. Allen and D. J. Tildesley,
*Computer simulation of liquids*, Oxford university press: New York, 1991. - ↑ M. Parrinello and A. Rahman, Phys. Rev. Lett. 45, 1196 (1980).
- ↑ M. Parrinello and A. Rahman, J. Appl. Phys. 52, 7182 (1981).