| Command | Input | Output | |
| thermo_style custom | global scalars | screen, log file | |
| dump custom | per-atom vectors | dump file | |
diff --git a/doc/Section_intro.html b/doc/Section_intro.html
index 5e7cd6e066..f9b00bb689 100644
--- a/doc/Section_intro.html
+++ b/doc/Section_intro.html
@@ -219,6 +219,7 @@ commands)
nudged elastic band
parallel replica dynamics
+temperature accelerated dynamics
parallel tempering
Pre- and post-processing
diff --git a/doc/Section_start.html b/doc/Section_start.html
index 4be3c89537..419414938f 100644
--- a/doc/Section_start.html
+++ b/doc/Section_start.html
@@ -327,6 +327,45 @@ build it. In the src/MAKE/Windows directory are some notes from users
on how they built LAMMPS under Windows, so you can look at their
instructions for tips. Good luck - we can't help you on this one.
+
(5) Changing the size limits in src/lmptype.h
+
+If you are running a very large problem (billions of atoms or more)
+and get a run-time error about the system being too big, either on a
+per-processor basis or in total size, then you may need to change one
+or more settings in src/lmptype.h and re-compile LAMMPS.
+
+As the documentation in that file explains, you have basically
+two choices to make:
+
+- set the data type size of integer atom IDs to 4 or 8 bytes
+
- set the data type size of integers that store the total system size to 4 or 8 bytes
+
+The default for atom IDs is 4-byte integers since there is a memory
+and communication cost for 8-byte integers. Non-molecular problems do
+not need atom IDs so this does not restrict their size. Molecular
+problems (which use IDs to define molecular topology), are limited to
+about 2 billion atoms (2^31) with 4-byte IDs. With 8-byte IDs they
+are effectively unlimited in size (2^63).
+
+The default for total system size quantities (like the number of atoms
+or timesteps) is 8-byte integers by default which is effectively
+unlimited in size (2^63). If your system does not support 8-byte
+integers, an error will be generated, and you will need to set
+"bigint" to 4-byte integers. This restricts your total system size to
+about 2 billion atoms or timesteps (2^31).
+
+Note that in src/lmptype.h there are also settings for the MPI data
+types associated with the integers that store atom IDs and total
+system sizes, which need to be set consistent with the associated C
+data types.
+
+In all cases, the size of problem that can be run on a per-processor
+basis is limited by 4-byte integer storage to about 2 billion atoms
+per processor (2^31), which should not normally be a restriction since
+such a problem would have a huge per-processor memory footprint due to
+neighbor lists and would run very slowly in terms of CPU
+secs/timestep.
+
2.3 Making LAMMPS with optional packages
diff --git a/doc/Section_start.txt b/doc/Section_start.txt
index ae747ded66..4faa069315 100644
--- a/doc/Section_start.txt
+++ b/doc/Section_start.txt
@@ -322,6 +322,45 @@ build it. In the src/MAKE/Windows directory are some notes from users
on how they built LAMMPS under Windows, so you can look at their
instructions for tips. Good luck - we can't help you on this one.
+(5) Changing the size limits in src/lmptype.h
+
+If you are running a very large problem (billions of atoms or more)
+and get a run-time error about the system being too big, either on a
+per-processor basis or in total size, then you may need to change one
+or more settings in src/lmptype.h and re-compile LAMMPS.
+
+As the documentation in that file explains, you have basically
+two choices to make:
+
+set the data type size of integer atom IDs to 4 or 8 bytes
+set the data type size of integers that store the total system size to 4 or 8 bytes :ul
+
+The default for atom IDs is 4-byte integers since there is a memory
+and communication cost for 8-byte integers. Non-molecular problems do
+not need atom IDs so this does not restrict their size. Molecular
+problems (which use IDs to define molecular topology), are limited to
+about 2 billion atoms (2^31) with 4-byte IDs. With 8-byte IDs they
+are effectively unlimited in size (2^63).
+
+The default for total system size quantities (like the number of atoms
+or timesteps) is 8-byte integers by default which is effectively
+unlimited in size (2^63). If your system does not support 8-byte
+integers, an error will be generated, and you will need to set
+"bigint" to 4-byte integers. This restricts your total system size to
+about 2 billion atoms or timesteps (2^31).
+
+Note that in src/lmptype.h there are also settings for the MPI data
+types associated with the integers that store atom IDs and total
+system sizes, which need to be set consistent with the associated C
+data types.
+
+In all cases, the size of problem that can be run on a per-processor
+basis is limited by 4-byte integer storage to about 2 billion atoms
+per processor (2^31), which should not normally be a restriction since
+such a problem would have a huge per-processor memory footprint due to
+neighbor lists and would run very slowly in terms of CPU
+secs/timestep.
+
:line
2.3 Making LAMMPS with optional packages :h4,link(2_3)