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3.1 Running examples
As a final check that compilation was successful, you may want to run some or
all of the examples (presently only one). To run the examples, you should follow this procedure:
- Edit the environment_variables file in the main QUANTUM ESPRESSO directory,
setting the following variables as needed:
BIN_DIR: directory where executables reside
PSEUDO_DIR: directory where pseudopotential files reside
TMP_DIR: directory to be used as temporary storage area
The default values of BIN_DIR and PSEUDO_DIR should be fine,
unless you have installed things in nonstandard places. The TMP_DIR
variable must point to a directory where you have read and write permissions,
with enough available space to host the temporary files produced by the
example runs, and possibly offering good I/O performance (i.e., don't
use an NFS-mounted directory). N.B. Use a dedicated directory,
because the example script will automatically delete all data inside TMP_DIR.
If you have compiled the parallel version of QUANTUM ESPRESSO (this
is the default if parallel libraries are detected), you will usually
have to specify a driver program (such as mpirun or mpiexec)
and the number of processors: see Sec.4.1 for
details. In order to do that, edit again the environment_variables
file
and set the PARA_PREFIX and PARA_POSTFIX variables as needed.
Parallel executables will be started with a command line like this:
$PARA_PREFIX neb.x $PARA_POSTFIX -inp file.in > file.out
For example, the command for IBM's POE looks like this:
poe neb.x -procs 4 -inp file.in > file.out
therefore you will need to set PARA_PREFIX="poe", PARA_POSTFIX="-procs 4".
Furthermore, if your machine does not support interactive use, you
must run the commands specified below through the batch queuing
system installed on that machine. Ask your system administrator for
instructions.
Go to NEB/examples and execute:
./run_example
This will create a subdirectory results/ containing the input and
output files generated by the calculation.
The reference/ subdirectory contains
verified output files, that you can check your results against. They
were generated on a Linux PC using the Intel compiler. On different
architectures the precise numbers could be slightly different, in
particular if different FFT dimensions are automatically selected. For
this reason, a plain diff of your results against the reference data
doesn't work, or at least, it requires human inspection of the
results.
Next: 4 Parallelism
Up: 3 Compilation
Previous: 3 Compilation
Contents
Layla Martin-Samos Colomer
2012-11-21