Opening nextPYP files on ChimeraX or IMOD - data type (12)

[AriaGarrett]

I am never able to externally open .rec or .mrc files from nextpyp tomography data - whether I download or access from the folder directly. I often will get the error that data type (12) is not 8 or 16 bit integers or 32 bit floats when I try and open via ChimeraX or IMOD.

I'm wondering if there is a setting known to commonly cause this problem, or alternative ways to convert the data.

Thank you!

[abartesaghi]

By default, nextPYP saves intermediate .mrc and .rec files in 16-bit integer format to reduce disk usage. You can disable this behavior by unchecking the option Save tomograms in 16-bits in the Tomogram reconstruction tab of the Pre-processing block. This will store tomograms in 32-bit format, which is more widely supported but requires twice the disk space.

A similar option is available in the Frame alignment tab, which controls the precision used for saving raw and aligned tilt-series files.

IMOD versions newer than 5.1.0 can read 16-bit precision files (this is the version nextPYP uses internally). I do not know about Chimera, but you can always convert a file from 16-bit to 32-bit using the command: newstack -mode 2 input.mrc output.mrc (assuming you have IMOD >= 5.1.0 installed).

[AriaGarrett]

Thank you! This was definitely my problem.