To get started lets test how to run a simple calculation using the PWscf pw.x code from Quantum ESPRESSO.
Within the VM, all the installed code are already added to the PATH environmental variable, hence they can all be accessed by simply writing their name in the terminal.
To pass an input file to pw.x we will use the character < which redirects the content of a file to the STDIN of the launched program.
pw.x < INPUT_FILE_NAME
In this way, the output of the code will actually be displayed within the terminal.
In order to save it to a file we will use > which redirects the STDOUT of the program to a file.
pw.x < INPUT_FILE_NAME > OUTPUT_FILE_NAME
You could also add & to the end of the command to run the program in background (it will not keep the terminal occupied)
pw.x < INPUT_FILE_NAME > OUTPUT_FILE_NAME &
In this case you could use a command such as tail -f OUTPUT_FILE_NAME to inspect the output file while it is being generated (Use CTRL+C in order to exit/kill tail -f).
For all exercises we will assume that you have downloaded the repository and are working in the respective folder for each exercise
- Copy the provided input files into this folder
cp ../files/NaCl.scf.in . - Copy or link the pseudopotential files for Na and Cl inside a folder named
pseudoin the same path of the input file
cp -r ../files/pseudo/ . - Run the code pw.x from terminal using the command
pw.x < Na.scf.in > Na.scf.out - Run the code pw.x from terminal using the command
pw.x < Na.scf.in > Na.scf.out - Inspect the output file using your preferred editor or command line tool (eg
vim,nano,less,cat).
The output files are written in human readable form, so you can try to skim through it to see what information is available