CMDF File

What are CMDF files and how to open them

Are you having problems opening a CMDF file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your CMDF files.

What is a CMDF file?

A .CMDF file is a CrystalMaker Data Format file.

CrystalMaker Data Format files store complete, binary crystallographic structure data produced by CrystalMaker version 7 through version 9. They capture full 3D models of crystals and molecules, including unit cell geometry, atomic positions and species, symmetry settings, orientation and rendering details, so that the structure can be re-opened later and viewed or processed exactly as when it was saved.

These files are written by CrystalMaker software and are not used for interchange in editable form - other formats like its text-based "CrystalMaker text format" exist for that purpose. The binary file enables quick loading of structures into CrystalMaker, CrystalDiffract or SingleCrystal (produced by CrystalMaker Software) with all of the display, symmetry and lattice data preserved.

Files begin with a unique byte signature string marking the format identity: at offset 0 is the ASCII string "CMDFCrystalMakerM…", followed by specific markers such as "REND", "MODL", "SURF", "CELL", "VIEW" and "SYMM" at fixed offsets within the file that identify internal sections for rendering, model, surface, lattice cell, view orientation and symmetry data respectively.

How to open CMDF files

Important: Different programs may use files with the CMDF file extension for different purposes, so unless you are sure which format your CMDF file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested four different CMDF openers which you will find listed below.

Last updated: August 31, 2026

Various apps that use files with this extension

These apps are known to open certain types of CMDF files. Remember, different programs may use CMDF files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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File.org helps thousands of users every day, and we would love to hear from you if you have additional information about CMDF file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.