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wwpdb-dictionaries / mmcif_pdbx

wwPDB PDBx/mmCIF Dictionary
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pdbx_formula_weight is used in current entries - documentation says otherwise #39

Closed samirelanduk closed 3 years ago

samirelanduk commented 3 years ago

The online mmCIF dictionary documentation states that the struct category has a field pdbx_formula_weight, but states that is not used in currrent PDB entries.

In fact it seems that this data item is very widely used - 6FKT uses it to give just one of many examples.

epeisach commented 3 years ago

I will undertake a recalculation of usage.

epeisach commented 3 years ago

We have regenerated the counts. However, you were explicitly asking about struct.pdbx_formula_weight in which there are no counts. I think you might be confusing presence in a model file with those containing data. In CIF "?" is essentially an empty value - and we are not counting those. You mention 6FKT and you will notice that _struct.pdbx_formula_weight is "?". Is this what you were referring to?

samirelanduk commented 3 years ago

Hi - thanks for looking into this. Yes that is what I was referring to. I think the language used is a little confusing on the page (I would argue that 6FKT is 'using' _struct.pdbx_formula_weight by having it present) but thank you for clarifying this.