From 77789f9ed8a4772d4ef9a2940d800dbb20ba46a3 Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Sun, 6 Sep 2020 00:07:53 -0400
Subject: [PATCH] small tweaks

---
 doc/src/Build_settings.rst  | 22 ++++++++++++++--------
 doc/src/_ext/tab_or_note.py |  2 +-
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/doc/src/Build_settings.rst b/doc/src/Build_settings.rst
index 6a09e7d4bf..0c56b85c86 100644
--- a/doc/src/Build_settings.rst
+++ b/doc/src/Build_settings.rst
@@ -185,20 +185,25 @@ The default setting of "smallbig" is almost always adequate.
 
    .. tab:: CMake build
 
+      With CMake the choice of integer types is made via setting a
+      variable during configuration.
+
       .. code-block:: bash
 
          -D LAMMPS_SIZES=value   # smallbig (default) or bigbig or smallsmall
 
+      If the variable is not set explicitly, "smallbig" is used.
+
    .. tab:: Traditional build
 
-      If you want a setting different from the default, you need to edit your
-      machine Makefile.
+      If you want a setting different from the default, you need to edit the
+      ``LMP_INC`` variable setting your machine Makefile.
 
-   .. code-block:: make
+      .. code-block:: make
 
-      LMP_INC = -DLAMMPS_SMALLBIG    # or -DLAMMPS_BIGBIG or -DLAMMPS_SMALLSMALL
+         LMP_INC = -DLAMMPS_SMALLBIG    # or -DLAMMPS_BIGBIG or -DLAMMPS_SMALLSMALL
 
-The default setting is ``-DLAMMPS_SMALLBIG`` if nothing is specified
+      The default setting is ``-DLAMMPS_SMALLBIG`` if nothing is specified
 
 LAMMPS system size restrictions
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -218,7 +223,7 @@ The "bigbig" setting increases the latter two limits.  It allows for:
 * image flags = roll over at about 1 million (2\^20)
 
 The "smallsmall" setting is only needed if your machine does not
-support 8-byte integers.  It allows for:
+support 64-bit integers.  It allows for:
 
 * total atom count = 2\^31 atoms (about 2 billion)
 * total timesteps = 2\^31 (about 2 billion)
@@ -234,8 +239,9 @@ more than 2 billion atoms, you need the "bigbig" setting.
 
 Regardless of the total system size limits, the maximum number of atoms
 per MPI rank (local + ghost atoms) is limited to 2 billion for atomic
-systems and 500 million for systems with bonds (due to using the 2
-upper bits of the local atom index for storing special bonds labels).
+systems and 500 million for systems with bonds (the additional
+restriction is due to using the 2 upper bits of the local atom index
+in neighbor lists for storing special bonds info).
 
 Image flags store 3 values per atom in a single integer which count the
 number of times an atom has moved through the periodic box in each
diff --git a/doc/src/_ext/tab_or_note.py b/doc/src/_ext/tab_or_note.py
index da8d6b9c5c..43b70d6050 100644
--- a/doc/src/_ext/tab_or_note.py
+++ b/doc/src/_ext/tab_or_note.py
@@ -1,7 +1,7 @@
 
 def replace_tabs_handler(app, docname, source):
     """ When builder is not 'html', remove 'tabs' directive
-    and replace 'tab' directive with 'admonition'"""
+    and replace any 'tab' directive with 'admonition'"""
     if app.builder.name != 'html':
         for i in range(len(source)):
             str = source[i].replace('.. tabs::','')