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COMCIFS / Powder_Dictionary

CIF definitions for powder diffraction
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description of pd_block.id contradicts PD_BLOCK: can't loop a Set #43

Closed rowlesmr closed 1 year ago

rowlesmr commented 1 year ago

PD_BLOCK is a Set category, which only allows a single value per data name.

The definition of _pd_block.id says (in part):

It is possible to loop more than one ID for a block: if changes or additions are made to the block later, a new ID may be assigned, but the original name should be retained.

Should the category of PD_BLOCK or the definition of _pd_block.id be changed?

There are no other data names associated with PD_BLOCK.

jamesrhester commented 1 year ago

Well that's pretty interesting. A block can have multiple identifiers, but they are all unique in the whole universe, so not a problem! Yes, PD_BLOCK should just be a Loop category.