Adapt examples/work/test_pw.py to point to the correct QE path and pseudos

[szoupanos]

This file is outdated and it uses wrong path to the QE plugin (e.g. from aiida.orm.calculation.job.quantumespresso.pw import PwCalculation) and points to the wrong place for the needed psedopotentials.

It is an easy fix. Maybe other scripts should be updated too.

[sphuber]

For this particular example there are three potential solutions as I see it

1. Put aiida_quantumespresso import in try/except and raise exception when it is not installed
2. Add aiida_quantumespresso as a dependency of aiida_core
3. Remove or move the examples to aiida_quantumespresso

The second option is something we definitely don't want to do I think. The first one would be an option, however, given that it really is a quantum espresso example, I think it really belongs in that repository. But I already have examples there that are almost identical and even provide a nice command line interface.

Conclusion: shall I just remove the obsolete QE specific examples?

[sphuber]

@giovannipizzi just added you to assignees to get your opinion on the above discussion.

[giovannipizzi]

I agree: 2 is not viable, I would avoid 1, and I would go for 3. If there are better examples, let's just remove it. If it's simpler/still makes sense to keep, let's move it. Thanks!

[sphuber]

Even the non-QE examples in examples/work are extremely outdated and most of them don't run. I am tempted to remove all of them and replace them by some simple new and concise ones.

[szoupanos]

Thanks for the fast reaction on this - Actually I did not manage to see it early enough to reply in time and provide comments.

Why did you remove also test_pw.py?
Do we have a simple submission script that shows how to submit calculations?
In case someone is not interested to use workchains/new workflows?

[szoupanos]

Moreover, the submit(JobCalc, **inputs)) that was mentioned at the end of the test_pw and the JobCalc.get_inputs_template() is somewhere documented?
Is this the new approach for submitting calculations?

[sphuber]

I could whip up an example based on the TemplatereplacerCalculation job calculation class, but for the actual run call to work we need to pass a Code. For the travis-tests we use the torquessh-doubler dummy code, but I don't think we can easily use this for this particular example. I think it will only make it more confusing. However, without a proper code, I am not sure how I can complete an example that actually "runs" like the dummy workchains for example. Any ideas?

[giovannipizzi]

I think that if there is no example with the new way of submitting calcs, an example should be added (but this cannot be on QE, he test_pw is now in the aiida-qe plugin).
It should be doable (at least to show that it works) also with the TemplatereplacerCalculation (in the tests, a code is created for it).

[szoupanos]

Thanks for the info. I found the test_pw at the QE repository (I assume that they point to the correct pseudos etc - I did not test them but I will soon).
Let's have a small chat during the next AiiDA meeting about the new calculation submission (why it is needed, what does it serve, how it is used etc).