Urgent need to validate the parameters Dict

[danieleongari]

Dicts like "IsothermParameters" are very dangerous, since a typo in the key makes the work chain neglect that key and use the default settings. Typical cases are key that were changed in more recent versions, such as:

• ff_framework instead of forcefield
• ff_tail_corrections instead of ff_tailcorr
• ff_shifted instead of ff_shift

Therefore, there is an urgent need to validate the dictionary (that should not contain keys that are not in the default dictionary) and possibly make this work so that the outer work chain already complains at the start if any Isotherm sub-work chain gets an unexpected Dict as input.

[danieleongari]

Another common source of error, is to use scientific notation (e.g., 10e-5) in the YAML file with the parameters, and use a parser that does not convert it to float }(e.g., yaml.safe_load(), while ruamel should work fine. The work chain crashes when this produces and error, while an initial validation would immediately reject the submission.

[danieleongari]

Yet another source of error are None values that are by default written in YAML files as null. Therefore, if None is used in a YAML file, this will be interpreted as a string, causing troubles for the work chain. The case here is for the key pressure_list.

[ltalirz]

PR https://github.com/lsmo-epfl/aiida-lsmo/pull/62 should address all of the above mentioned issues:

• mistyped keys will be recognized when passing the builder to the workchain (and raise an exception)
• the type of fields is validated as well, i.e. if a value is not properly converted from yaml (1e-5), it will raise
• The behavior of the pressure_list and temperature_list keys has been modified slightly: if you don't want to provide them, simply don't set the key (instead of setting the key to None)