From 0e644f1ebc1c972df0504aa5bfa5cb521c9b6436 Mon Sep 17 00:00:00 2001 From: sjplimp Date: Fri, 1 Aug 2008 15:10:00 +0000 Subject: [PATCH] git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@2015 f3b2605a-c512-4ea7-a41b-209d697bcdaa --- doc/fix_addforce.html | 30 ++++++++++++++++++++++-------- doc/fix_addforce.txt | 30 ++++++++++++++++++++++-------- 2 files changed, 44 insertions(+), 16 deletions(-) diff --git a/doc/fix_addforce.html b/doc/fix_addforce.html index a288b8231a..9b3fe8f9e9 100644 --- a/doc/fix_addforce.html +++ b/doc/fix_addforce.html @@ -33,15 +33,24 @@ a channel.

Restart, fix_modify, output, run start/stop, minimize info:

No information about this fix is written to binary restart -files. None of the fix_modify options -are relevant to this fix. +files.

-

This fix computes a 3-vector of forces, which can be accessed by -various output commands. This is the total -force on the group of atoms before the forces on individual atoms are -changed by the fix. The vector values calculated by this fix are -"extensive", meaning they scale with the number of atoms in the -simulation. +

The fix_modify energy option is supported by this +fix to add the potential "energy" inferred by the added force to the +system's potential energy as part of thermodynamic +output. This is a fictitious quantity but is +needed so that the minimize command can include the +forces added by this fix in a consistent manner. I.e. there is a +decrease in potential energy when atoms move in the direction of the +added force. +

+

This fix computes a scalar and a 3-vector of forces, which can be +accessed by various output commands. The +scalar is the potential energy discussed above. The vector is the +total force on the group of atoms before the forces on individual +atoms are changed by the fix. The scalar vector values calculated by +this fix are "extensive", meaning they scale with the number of atoms +in the simulation.

No parameter of this fix can be used with the start/stop keywords of the run command. @@ -49,6 +58,11 @@ the run command.

The forces due to this fix are imposed during an energy minimization, invoked by the minimize command.

+

IMPORTANT NOTE: If you want the fictitious potential energy associated +with the added forces to be included in the total potential energy of +the system (the quantity being minimized), you MUST enable the +fix_modify energy option for this fix. +

Restrictions: none

Related commands: diff --git a/doc/fix_addforce.txt b/doc/fix_addforce.txt index cedbd0ee80..014db2b820 100644 --- a/doc/fix_addforce.txt +++ b/doc/fix_addforce.txt @@ -30,15 +30,24 @@ a channel. [Restart, fix_modify, output, run start/stop, minimize info:] No information about this fix is written to "binary restart -files"_restart.html. None of the "fix_modify"_fix_modify.html options -are relevant to this fix. +files"_restart.html. -This fix computes a 3-vector of forces, which can be accessed by -various "output commands"_Section_howto.html#4_15. This is the total -force on the group of atoms before the forces on individual atoms are -changed by the fix. The vector values calculated by this fix are -"extensive", meaning they scale with the number of atoms in the -simulation. +The "fix_modify"_fix_modify.html {energy} option is supported by this +fix to add the potential "energy" inferred by the added force to the +system's potential energy as part of "thermodynamic +output"_thermo_style.html. This is a fictitious quantity but is +needed so that the "minimize"_minimize.html command can include the +forces added by this fix in a consistent manner. I.e. there is a +decrease in potential energy when atoms move in the direction of the +added force. + +This fix computes a scalar and a 3-vector of forces, which can be +accessed by various "output commands"_Section_howto.html#4_15. The +scalar is the potential energy discussed above. The vector is the +total force on the group of atoms before the forces on individual +atoms are changed by the fix. The scalar vector values calculated by +this fix are "extensive", meaning they scale with the number of atoms +in the simulation. No parameter of this fix can be used with the {start/stop} keywords of the "run"_run.html command. @@ -46,6 +55,11 @@ the "run"_run.html command. The forces due to this fix are imposed during an energy minimization, invoked by the "minimize"_minimize.html command. +IMPORTANT NOTE: If you want the fictitious potential energy associated +with the added forces to be included in the total potential energy of +the system (the quantity being minimized), you MUST enable the +"fix_modify"_fix_modify.html {energy} option for this fix. + [Restrictions:] none [Related commands:]