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@ -135,6 +135,7 @@ commands)
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charged pairwise potentials: Coulombic, point-dipole
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manybody potentials: EAM, Finnis/Sinclair EAM, modified EAM (MEAM), \
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embedded ion method (EIM), Stillinger-Weber, Tersoff, AI-REBO, ReaxFF, COMB
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electron force field (eFF)
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coarse-grained potentials: DPD, GayBerne, REsquared, colloidal, DLVO
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mesoscopic potentials: granular, Peridynamics
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bond potentials: harmonic, FENE, Morse, nonlinear, class 2, \
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@ -22,16 +22,17 @@ compute myTemp all temp/deform/eff :pre
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[Description:]
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Define a computation that calculates the temperature of a group of
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nuclei and electrons using the electron force field, after subtracting
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out a streaming velocity induced by the simulation box changing size
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and/or shape, for example in a non-equilibrium MD (NEMD) simulation.
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The size/shape change is induced by use of the "fix
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deform/eff"_fix_deform_eff.html command. A compute of this style is
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created by the "fix nvt/sllod/eff"_fix_nvt_sllod_eff.html command to
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compute the thermal temperature of atoms for thermostatting purposes.
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A compute of this style can also be used by any command that computes
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a temperature, e.g. "thermo_modify"_thermo_modify.html, "fix
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npt/eff"_fix_nh.html, etc.
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nuclei and electrons in the "electron force field"_pair_eff.html
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model, after subtracting out a streaming velocity induced by the
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simulation box changing size and/or shape, for example in a
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non-equilibrium MD (NEMD) simulation. The size/shape change is
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induced by use of the "fix deform/eff"_fix_deform_eff.html command. A
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compute of this style is created by the "fix
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nvt/sllod/eff"_fix_nvt_sllod_eff.html command to compute the thermal
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temperature of atoms for thermostatting purposes. A compute of this
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style can also be used by any command that computes a temperature,
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e.g. "thermo_modify"_thermo_modify.html, "fix npt/eff"_fix_nh.html,
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etc.
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The calculation performed by this compute is exactly like that
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described by the "compute temp/deform"_compute_temp_deform.html
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@ -23,9 +23,10 @@ compute mine flow temp/region/eff boundary :pre
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[Description:]
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Define a computation that calculates the temperature of a group of
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nuclei and electrons wihtin a geometric region using the electron
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force field. A compute of this style can be used by commands that
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compute a temperature, e.g. "thermo_modify"_thermo_modify.html.
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nuclei and electrons in the "electron force field"_pair_eff.html
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model, within a geometric region using the electron force field. A
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compute of this style can be used by commands that compute a
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temperature, e.g. "thermo_modify"_thermo_modify.html.
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The operation of this compute is exactly like that described by the
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"compute temp/region"_compute_temp_region.html command, where the
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@ -60,7 +60,10 @@ interactions (<A HREF = "pair_style.html">pair_style</A>).
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<P>The Ff and Fr terms are added by this fix on a per-particle basis.
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</P>
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<P>Ff is a frictional drag or viscous damping term proportional to the
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particle's velocity (including the electronic radial degrees of freedom). The proportionality constant for each atom is computed as m/damp, where m is the mass of the particle and damp is the damping factor specified by the user.
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particle's velocity (including the electronic radial degrees of
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freedom). The proportionality constant for each atom is computed as
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m/damp, where m is the mass of the particle and damp is the damping
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factor specified by the user.
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</P>
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<P>Fr is a force due to solvent atoms at a temperature T randomly bumping
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into the particle. As derived from the fluctuation/dissipation
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@ -73,15 +76,18 @@ the direction and magnitude of this force as described in
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a Gaussian random number) for speed.
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</P>
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<P>Note that the thermostat effect of this fix is applied to the
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translational and electronic radial degrees of freedom for the particles in a system. The translational degrees of freedom can also have a bias
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velocity removed from them before thermostatting takes place; see the
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description below.
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translational and electronic radial degrees of freedom for the
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particles in a system. The translational degrees of freedom can also
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have a bias velocity removed from them before thermostatting takes
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place; see the description below.
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</P>
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<P>IMPORTANT NOTE: Unlike the <A HREF = "fix_nh_eff.html">fix nvt/eff</A> command which
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performs Nose/Hoover thermostatting AND time integration, this fix
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does NOT perform time integration. It only modifies forces to effect
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thermostatting. Thus you must use a separate time integration fix,
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like <A HREF = "fix_nve_eff.html">fix nve/eff</A> to actually update the velocities (including electronic radial velocities) and positions of atoms (nuclei and electrons) using the modified forces. Likewise, this fix
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like <A HREF = "fix_nve_eff.html">fix nve/eff</A> to actually update the velocities
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(including electronic radial velocities) and positions of atoms
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(nuclei and electrons) using the modified forces. Likewise, this fix
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should not normally be used on atoms that also have their temperature
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controlled by another fix - e.g. by <A HREF = "fix_nh.html">fix nvt/eff</A> command.
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</P>
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@ -106,13 +112,14 @@ the remaining thermal degrees of freedom, and the bias is added back
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in.
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</P>
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<P>The <I>damp</I> parameter is specified in time units and determines how
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rapidly the temperature is relaxed. For example, a value of 0.1
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means to relax the temperature in a timespan of 100 timesteps (for the default 0.001 timesteps and fmsec unit used in eFF - see the <A HREF = "units.html">units</A> command).
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The damp factor can be thought of as inversely related to the
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viscosity of the solvent. I.e. a small relaxation time implies a
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hi-viscosity solvent and vice versa. See the discussion about gamma
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and viscosity in the documentation for the <A HREF = "fix_viscous.html">fix
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viscous</A> command for more details.
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rapidly the temperature is relaxed. For example, a value of 0.1 means
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to relax the temperature in a timespan of 100 timesteps (for the
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default 0.001 timesteps and fmsec unit used in eFF - see the
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<A HREF = "units.html">units</A> command). The damp factor can be thought of as
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inversely related to the viscosity of the solvent. I.e. a small
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relaxation time implies a hi-viscosity solvent and vice versa. See
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the discussion about gamma and viscosity in the documentation for the
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<A HREF = "fix_viscous.html">fix viscous</A> command for more details.
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</P>
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<P>The random # <I>seed</I> must be a positive integer. A Marsaglia random
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number generator is used. Each processor uses the input seed to
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@ -182,7 +189,7 @@ LAMMPS</A> section for more info.
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</P>
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<P><B>Related commands:</B>
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</P>
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<P><A HREF = "fix_nh.html">fix nvt/eff</A>
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<P><A HREF = "fix_langevin.html">fix langevin</A>
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</P>
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<P><B>Default:</B>
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</P>
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@ -15,10 +15,10 @@
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</P>
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<P>pair_style eff/cut cutoff eradius_limit_flag pressure_flag
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</P>
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<P>cutoff = global cutoff for Coulombic interactions
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eradius_limit_flag = 0 or 1 for whether electron size is restrained (optional)
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pressure_flag = 0 or 1 to define the type of pressure calculation (optional)
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</P>
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<UL><LI>cutoff = global cutoff for Coulombic interactions
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<LI>eradius_limit_flag = 0 or 1 for whether electron size is restrained (optional)
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<LI>pressure_flag = 0 or 1 to define the type of pressure calculation (optional)
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</UL>
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<P><B>Examples:</B>
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</P>
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<PRE>pair_style eff/cut 39.7
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@ -14,7 +14,7 @@ pair_style eff/cut cutoff eradius_limit_flag pressure_flag
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cutoff = global cutoff for Coulombic interactions
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eradius_limit_flag = 0 or 1 for whether electron size is restrained (optional)
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pressure_flag = 0 or 1 to define the type of pressure calculation (optional)
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pressure_flag = 0 or 1 to define the type of pressure calculation (optional) :ul
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[Examples:]
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