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@ -57,6 +57,11 @@ optional keyword <I>scale</I> is used, gamma can scaled up or down by the
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specified factor for atoms of that type. It can be used multiple
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times to adjust gamma for several atom types.
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</P>
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<P>IMPORTANT NOTE: You should specify gamma in force/velocity units.
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This is not the same as mass/time units, at least for some of the
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LAMMPS <A HREF = "units.html">units</A> options like "real" or "metal" that are not
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self-consistent.
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</P>
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<P>In a Brownian dynamics context, gamma = kT / D, where k = Boltzmann's
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constant, T = temperature, and D = particle diffusion coefficient. D
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can be written as kT / (3 pi eta d), where eta = dynamic viscosity of
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@ -76,8 +81,8 @@ viscous damping term as fix viscous and adds a random force to each
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atom. Hence if using fix <I>langevin</I> you do not typically need to use
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fix <I>viscous</I>. Also note that the gamma of fix viscous is related to
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the damping parameter of <A HREF = "fix_langevin.html">fix langevin</A>, except that
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the units of gamma are force/velocity (or mass/time) and the units of
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damp are time, so that it can more easily be used as a thermostat.
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the units of gamma are force/velocity and the units of damp are time,
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so that it can more easily be used as a thermostat.
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</P>
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<P><B>Restart, fix_modify, output, run start/stop, minimize info:</B>
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</P>
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@ -47,6 +47,11 @@ optional keyword {scale} is used, gamma can scaled up or down by the
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specified factor for atoms of that type. It can be used multiple
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times to adjust gamma for several atom types.
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IMPORTANT NOTE: You should specify gamma in force/velocity units.
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This is not the same as mass/time units, at least for some of the
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LAMMPS "units"_units.html options like "real" or "metal" that are not
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self-consistent.
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In a Brownian dynamics context, gamma = kT / D, where k = Boltzmann's
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constant, T = temperature, and D = particle diffusion coefficient. D
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can be written as kT / (3 pi eta d), where eta = dynamic viscosity of
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@ -66,8 +71,8 @@ viscous damping term as fix viscous and adds a random force to each
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atom. Hence if using fix {langevin} you do not typically need to use
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fix {viscous}. Also note that the gamma of fix viscous is related to
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the damping parameter of "fix langevin"_fix_langevin.html, except that
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the units of gamma are force/velocity (or mass/time) and the units of
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damp are time, so that it can more easily be used as a thermostat.
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the units of gamma are force/velocity and the units of damp are time,
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so that it can more easily be used as a thermostat.
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[Restart, fix_modify, output, run start/stop, minimize info:]
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