Recommendations#

Working with this Script#

  1. Work on the exercises in the given order. You may need some of the results you calculate for comparison.

  2. Read the whole exercise before you start working on it. Often technical hints are given at the end.

  3. Programs can crash. So check your outputs as soon as possible to ensure your calculations worked. And sometimes preparing the input and running the program is much faster than finding the right number in the output.

  4. Always make sure to redirect your standard output to an appropriate file by using the output operator (“>”). This way, it ensures that no vital data is lost and we can follow your workflow.

  5. Prepare an LibreOffice sheet (or similar) with a collection of your results. Checking them this way is much easier for us.

Trouble Shooting#

Many programs may cause many problems. Therefore you should follow some simple guidelines to identify their origins:

  • “Crap in, crap out”: Always check your input (input structures, file formats, input file, chosen keywords, etc.) before you start a calculation.

  • If a calculation stops abnormally, check the output (e.g. orca.out, job.last, etc.) and error files first.

  • Read your output and error files carefully. Especially check the last lines of the output file for error messages that hint at what may have caused the problem.

  • If you identified the problem (maybe you have to start at the first point again), check the program manual for additional options or troubleshooting help, fix the problem, and restart your calculation.

  • If the calculation still stops abnormally and all other possibilities and options are exhausted, prepare a detailed description of the problem, the output/error messages and contact one of the tutors.

Further reading#

If this is your first time working with Linux or quantum chemistry software, fear not; we still have you covered. You can find additional resources in our quantum chemistry II script: