If Octopus works properly on your system (i.e. you can recreate the results in the tutorials but you have troubles using it for your own work, here are some things to try. Please feel free to add your own ideas here.

Read parser.log

If you look at the file exec/parser.log , it will tell you the value of the variables that you set with the inp file, as well as all the variables which are taking their default value. This can sometimes be helpful in understanding the behavior of the program.

Use OutputDuringSCF

If you add OutputDuringSCF = yes to your input file, you can examine the results of each iteration in the Self Consistent Field calculation. So if you also have the variable Output set to Output = density + potential, both the electron density and the Kohn-Sham, bare, exchange-correlation and Hartree potentials will be written to a folder (called, e.g., scf.0001 ) after each SCF iteration.

Set Debug

Set the variable Debug to info for some extra diagnostic info and a stack trace with any fatal error, trace to add a full stack strace, and trace_file to get a stack trace from each MPI task when running in parallel. See the next page for more details.