The CP2K project : input section GLOBAL

Section GLOBAL

Index of all sections. This section is located at __ROOT__%GLOBAL.

Section with general information regarding which kind of simulation to perform an parameters for the whole PROGRAM. This section can not be repeated and can not be optional.

Subsections

Section keywords

Keyword descriptions

BLACS_GRID
BLACS_GRID SQUARE
how to distribute the processors on the 2d grid needed by BLACS (and thus SCALAPACK)
This optional keyword expects a keyword. Default value: SQUARE
valid keywords:
  • SQUARE: Distribution by matrix blocks
  • ROW: Distribution by matrix rows
  • COLUMN: Distribution by matrix columns
PREFERRED_FFT_LIBRARY
PREFERRED_FFT_LIBRARY FFTW
Specifies the FFT library which should be preferred. If it is not available, use FFTW if this is linked in, if FFTW is not available use FFTSG. Improved performance with FFTW can be obtained specifying a proper value for FFTW_PLAN_TYPE. Contrary to earlier CP2K versions, all libraries will result in the same grids, i.e. the subset of grids which all FFT libraries can transform. See EXTENDED_FFT_LENGTHS if larger FFTs or grids that more precisely match a given cutoff are needed, or older results need to be reproduced. FFTW is often (close to) optimal, and well tested with CP2K.
This optional keyword expects a keyword. Default value: FFTW
valid keywords:
  • FFTSG: Stefan Goedecker FFT, always available, will be used in case a FFT lib is specified and not available
  • FFTW: a fast portable FFT library. Recommended. This will use either FFTW2 or FFTW3, as availableSee also the FFTW_ARRAYS_ALIGNED, FFTW_PLAN_TYPE, and FFTW_WISDOM_FILE_NAME keywords.
  • FFTESSL: available/tuned for IBM machines
  • FFTACML: available/tuned for AMD machines (buggy & untested)
  • FFTMKL: available/tuned for INTEL machines (untested in parallel)
  • FFTSCI: available/tuned for SGI machines (untested)
  • FFTCU: available/tuned for NVIDIA GPUs (single precision only, untested)

This keyword cites following reference: [Frigo2005]
FFTW_WISDOM_FILE_NAME
FFTW_WISDOM_FILE_NAME wisdom.dat
The name of the file that contains wisdom (pre-planned FFTs) for use with FFTW3. Using wisdom can significantly speed up the FFTs (see the FFTW homepage for details). Note that wisdom is not transferable between different computer (architectures). Wisdom can be generated using the fftw-wisdom tool that is part of the fftw installation. cp2k/tools/cp2k-wisdom is a script that contains some additional info, and can help to generate a useful default for /etc/fftw/wisdom or particular values for a given simulation.
This optional keyword expects a string. Default value: /etc/fftw/wisdom
FFTW_PLAN_TYPE
FFTW_PLAN_TYPE PATIENT
FFTW can have improved performance if it is allowed to plan with explicit measurements which strategy is best for a given FFT. While a plan based on measurements is generally faster, differences in machine load will lead to different plans for the same input file, and thus numerics for the FFTs will be slightly different from run to run.PATIENT planning is recommended for long ab initio MD runs.
This optional keyword expects a keyword. Default value: ESTIMATE
valid keywords:
  • ESTIMATE: Quick estimate, no runtime measurements.
  • MEASURE: Quick measurement, somewhat faster FFTs.
  • PATIENT: Measurements trying a wider range of possibilities.
  • EXHAUSTIVE: Measurements trying all possibilities - use with caution.

This keyword cites following reference: [Frigo2005]
FFTW_ARRAYS_ALIGNED
FFTW_ARRAYS_ALIGNED NO
FFTW3 can make use of SIMD (e.g SSE/AltiVec) instructions for improved performance provided the FFT arrays are aligned correctly. There is no platform-independent way to achieve this, although most moderncompilers will align the arrays correctly. This flag is used totell FFTW3 if it can generate plans with SIMD instructions.
This optional keyword expects a logical
This keyword behaves as a switch T . Default value: T
This keyword cites following reference: [Frigo2005]
EXTENDED_FFT_LENGTHS
EXTENDED_FFT_LENGTHS
Use fft library specific values for the allows number of points in FFTs. The default is to use the internal FFT lengths. For external fft libraries this may create an error at the external library level, because the length provided by cp2k is not supported by the external library. In this case switch on this keyword to obtain, with certain fft libraries, lengths matching the external fft library lengths, or larger allowed grids, or grids that more precisely match a given cutoff. IMPORTANT NOTE: in this case, the actual grids used in CP2K depends on the FFT library. A change of FFT library must therefore be considered equivalent to a change of basis, which implies a change of total energy.
This optional keyword expects a logical
This keyword behaves as a switch T . Default value: F
FFT_POOL_SCRATCH_LIMIT
FFT_POOL_SCRATCH_LIMIT
Limits the memory usage of the FFT scratch pool, potentially reducing efficiency a bit
This optional keyword expects an integer. Default value: 15
ALLTOALL_SGL
ALLTOALL_SGL YES
All-to-all communication (FFT) should use single precision
This optional keyword expects a logical
This keyword behaves as a switch T . Default value: F
PRINT_LEVEL
PRINT_LEVEL HIGH
How much output is written out.
This optional keyword expects a keyword. Default value: MEDIUM
valid keywords:
  • SILENT: Almost no output
  • LOW: Little output
  • MEDIUM: Quite some output
  • HIGH: Lots of output
  • DEBUG: Everything is written out, useful for debugging purposes only
variants: IOLEVEL
PROGRAM_NAME
PROGRAM_NAME
Which program should be run
This optional keyword expects a keyword. Default value: CP2K
valid keywords:
  • ATOM: Runs single atom calculations
  • FARMING: Runs N independent jobs in a single run
  • TEST: Do some benchmarking and testing
  • CP2K: Runs one of the CP2K package
variants: PROGRAM
PROJECT_NAME
PROJECT_NAME
Name of the project (used to build the name of the trajectory, and other files generated by the program)
This optional keyword expects a word. Default value: PROJECT
variants: PROJECT
OUTPUT_FILE_NAME
OUTPUT_FILE_NAME {filename}
Name of the output file. Relevant only if automatically started (through farming for example). If empty uses the project name as basis for it.
This optional keyword expects a string. Default value:
RUN_TYPE
RUN_TYPE MD
Type of run that you want to perform Geometry optimization, md, montecarlo,...
This optional keyword expects a keyword. Default value: ENERGY_FORCE
valid keywords:
  • NONE: Perform no tasks
  • ENERGY: Computes energy
  • ENERGY_FORCE: Computes energy and forces
  • MD: Molecular Dynamics
  • GEO_OPT: Geometry Optimization
  • MC: Monte Carlo
  • SPECTRA: Computes absorption Spectra
  • DEBUG: Performs a Debug analysis
  • BSSE: Basis set superposition error
  • LR: Linear Response
  • PINT: Path integral
  • VIBRATIONAL_ANALYSIS: Vibrational analysis
  • BAND: Band methods
  • CELL_OPT: Cell optimization
  • WFN_OPT: Alias for ENERGY
  • WAVEFUNCTION_OPTIMIZATION: Alias for ENERGY
  • MOLECULAR_DYNAMICS: Alias for MD
  • GEOMETRY_OPTIMIZATION: Alias for GEO_OPT
  • MONTECARLO: Alias for MC
  • ELECTRONIC_SPECTRA: Alias for SPECTRA
  • LINEAR_RESPONSE: Alias for LR
  • NORMAL_MODES: Alias for VIBRATIONAL_ANALYSIS
  • RT_PROPAGATION: Real Time propagation run (fixed ionic positions)
  • EHRENFEST_DYN: Ehrenfest dynamics (using real time propagation of the wavefunction)
WALLTIME
WALLTIME real
Maximum execution time for this run. Time in seconds.
This optional keyword expects a real. Default value: -1.0000000000000000E+00
variants: WALLTI
ECHO_INPUT
ECHO_INPUT NO
If the input should be echoed to the output with all the defaults made explicit
This optional keyword expects a logical
This keyword behaves as a switch T . Default value: F
TRACE
TRACE
If a debug trace of the execution of the program should be written
This optional keyword expects a logical
This keyword behaves as a switch T . Default value: F
FLUSH_SHOULD_FLUSH
FLUSH_SHOULD_FLUSH
Flush output regularly, enabling this option might degrade performance significantly.
This optional keyword expects a logical
This keyword behaves as a switch T . Default value: F
TRACE_SYNC
TRACE_SYNC
For parallel TRACEd runs: synchronize the output of all processes,i.e. all output written by the parent node.This does not work for all possible types of CP2K runs (requires that timeset/timestop is called by all processes in sync, and fails otherwise)
This optional keyword expects a logical
This keyword behaves as a switch T . Default value: F
TRACE_MASTER
TRACE_MASTER
For parallel TRACEd runs: only the master node writes output.
This optional keyword expects a logical
This keyword behaves as a switch T . Default value: F
SEED
SEED
Initial seed for the global (pseudo)random number generator to create a stream of normally Gaussian distributed random numbers.
This optional keyword expects an integer. Default value: 2000
SAVE_MEM
SAVE_MEM
Some sections of the input structure are deallocated when not needed, and reallocated only when used. This reduces the required maximum memory
This optional keyword expects a logical
This keyword behaves as a switch T . Default value: F
ENABLE_UNSUPPORTED_FEATURES
ENABLE_UNSUPPORTED_FEATURES
This keywords enables the usage of unsupported features in a release version. It affects ONLY release versions of CP2K (no effects on development versions).
This optional keyword expects a logical
This keyword behaves as a switch T . Default value: F


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