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LANGEVIN_GAMMA and LANGEVIN_GAMMA_L

Friction coefficients ($ \gamma$) for atomic degrees of freedom used in Langevin dynamics (MDALGO=3) are defined via the parameter LANGEVIN_GAMMA:
LANGEVIN_GAMMA=[real array] friction coefficients (in ps$ ^{-1}$) for each species defined in POSCAR

Default
LANGEVIN_GAMMA=0.,...,0.

In addition to $ \gamma$ for atomic degrees of freedom, also the friction coefficient for lattice degrees of freedom has to be defined in the case of Parrinello-Rahman dynamics [79,80] (see 6.62.6):

LANGEVIN_GAMMA_L=[real] friction coefficients (in ps$ ^{-1}$) for lattice degrees of freedom

Default
LANGEVIN_GAMMA_L=0.

Note that Langevin dynamics with $ \gamma$ set to zero is equivalent to deterministic $ NVE$ ($ NpH$ in the case of Parrinello-Rahman method) dynamics.



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