From 72289a2606de599c42096dcaec078b3fc981237f Mon Sep 17 00:00:00 2001
From: sjplimp <sjplimp@f3b2605a-c512-4ea7-a41b-209d697bcdaa>
Date: Wed, 23 Mar 2011 13:54:53 +0000
Subject: [PATCH] git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@5811
f3b2605a-c512-4ea7-a41b-209d697bcdaa
---
doc/fix_box_relax.html | 13 +++++++++++++
doc/fix_box_relax.txt | 13 +++++++++++++
2 files changed, 26 insertions(+)
diff --git a/doc/fix_box_relax.html b/doc/fix_box_relax.html
index cf8bee4f74..1486e17651 100644
--- a/doc/fix_box_relax.html
+++ b/doc/fix_box_relax.html
@@ -82,6 +82,19 @@ re-scaled. This can be useful for leaving the coordinates of atoms in
a solid substrate unchanged and controlling the pressure of a
surrounding fluid.
</P>
+<P>IMPORTANT NOTE: Appling an external pressure to tilt dimensions <I>xy</I>,
+<I>xz</I>, <I>yz</I> can sometimes result in arbitrarily large values of the
+tilt dimensions, i.e. a dramatically deformed simulation box. This
+typically indicates that there is something badly wrong with how the
+simulation was constructed. The two most common sources of this error
+are applying a shear stress to a liquid system or specifying an
+external shear stress tensor that exceeds the yield stress of the
+solid. In either case the minimization is either not going to
+converge at all, or converge to a bogus conformation. Note that
+LAMMPS will not throw an error when the tilt value becomes extreme,
+but the final box may be unsuitable for running dynamics on, unless
+fix deform is used first to remap the box to a valid tilt value.
+</P>
<HR>
<P>The <I>couple</I> keyword allows two or three of the diagonal components of
diff --git a/doc/fix_box_relax.txt b/doc/fix_box_relax.txt
index 606cb3edab..510458504c 100644
--- a/doc/fix_box_relax.txt
+++ b/doc/fix_box_relax.txt
@@ -76,6 +76,19 @@ re-scaled. This can be useful for leaving the coordinates of atoms in
a solid substrate unchanged and controlling the pressure of a
surrounding fluid.
+IMPORTANT NOTE: Appling an external pressure to tilt dimensions {xy},
+{xz}, {yz} can sometimes result in arbitrarily large values of the
+tilt dimensions, i.e. a dramatically deformed simulation box. This
+typically indicates that there is something badly wrong with how the
+simulation was constructed. The two most common sources of this error
+are applying a shear stress to a liquid system or specifying an
+external shear stress tensor that exceeds the yield stress of the
+solid. In either case the minimization is either not going to
+converge at all, or converge to a bogus conformation. Note that
+LAMMPS will not throw an error when the tilt value becomes extreme,
+but the final box may be unsuitable for running dynamics on, unless
+fix deform is used first to remap the box to a valid tilt value.
+
:line
The {couple} keyword allows two or three of the diagonal components of
--
GitLab