Possible duplicate

[ajrzepiela]

In Instrument_schema.json:

"Cryogen": {
                "description": "Cryogen used in cooling the instrument and sample, usually nitrogen",
                "type": "string"
            },

"Holder_cryogen": {
                "description": "Type of cryogen used in the holder - if the holder is cooled seperately",
                "type": "string"
            },

[sbliven]

@sofyalaski which one gets used for mmcif?

[sofyalaski]

This one: _em_imaging.cryogen.
The second one has no association with PDBx according to conversions table

[ytittes]

I agree, usually these two will be identical, so it might make sense to just consolidate them into one entry.