info command — LAMMPS documentation

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# info command

## Syntax

    info args

- args = one or more of the following keywords: out, all, system, memory, communication, computes, dumps, fixes, groups, regions, variables, coeffs, styles, time, accelerator, fft or configuration

- out values = screen, log, append filename, overwrite filename

- styles values = all, angle, atom, bond, compute, command, dump, dihedral, fix, improper, integrate, kspace, minimize, pair, region

## Examples

    info system
    info groups computes variables
    info all out log
    info all out append info.txt
    info styles all
    info styles atom styles command

## Description

Print out information about the current internal state of the running LAMMPS process. This can be helpful when debugging or validating complex input scripts. Several output categories are available and one or more output categories may be requested. All category keywords take no arguments, only out and styles take arguments as shown below. The keywords are cumulative, may be abbreviated, and unknown keywords are ignored.

The out flag controls where the output is sent. It can only be sent to one target. By default this is the screen, if it is active. The log argument selects the log file instead. With the append and overwrite option, followed by a filename, the output is written to that file, which is either appended to or overwritten, respectively.

The all flag activates printing all categories listed below.

The configuration category prints some information about the LAMMPS version as well as architecture and OS it is run on.

The memory category prints some information about the current memory allocation of MPI rank 0 (this the amount of dynamically allocated memory reported by LAMMPS classes). Where supported, also some OS specific information about the size of the reserved memory pool size (this is where malloc() and the new operator request memory from) and the maximum resident set size is reported (this is the maximum amount of physical memory occupied so far).

The system category prints a general system overview listing. This includes the unit style, atom style, number of atoms, bonds, angles, dihedrals, and impropers and the number of the respective types, box dimensions and properties, force computing styles and more.

The communication category prints a variety of information about communication and parallelization: the MPI library version level, the number of MPI ranks and OpenMP threads, the communication style and layout, the processor grid dimensions, ghost atom communication mode, cutoff, and related settings.

The computes category prints a list of all currently defined computes, their IDs and styles and groups they operate on.

The dumps category prints a list of all currently active dumps, their IDs, styles, filenames, groups, and dump frequencies.

The fixes category prints a list of all currently defined fixes, their IDs and styles and groups they operate on.

The groups category prints a list of all currently defined groups.

The regions category prints a list of all currently defined regions, their IDs and styles and whether “inside” or “outside” atoms are selected.

The variables category prints a list of all currently defined variables, their names, styles, definition and last computed value, if available.

The coeffs category prints a list for each defined force style (pair, bond, angle, dihedral, improper) indicating which of the corresponding coefficients have been set. This can be very helpful to debug error messages like “All pair coeffs are not set”.

The accelerator category prints out information about compile time settings of included accelerator support for the GPU, KOKKOS, INTEL, and OPENMP packages.

Added in version 7Feb2024.

The fft category prints out information about the included 3d-FFT support. This lists the 3d-FFT engine, FFT precision, FFT library used by the FFT engine. If the KOKKOS package is included, the settings used for the KOKKOS package are displayed as well.

The styles category prints the list of styles available in the current LAMMPS binary. The styles keyword without option is the same as using the “all” option. One of the following options may be used to control which category of styles is printed out. To select multiple categories, the styles keyword needs to be used multiple times with the desired categories:

- all

- angle

- atom

- bond

- compute

- command

- dump

- dihedral

- fix

- improper

- integrate

- kspace

- minimize

- pair

- region

The time category prints the accumulated CPU and wall time for the process that writes output (usually MPI rank 0).

## Restrictions

none

## Related commands

print

## Default

The out option has the default screen.

The styles option has the default all.