Hi Smith, There is a viewHKL in ccp4, but that’s for viewing an intact MTZ. There are many tools for manipulating MTZ files in ccp4, but I doubt any of them was designed for you to fix a corrupt MTZ.
You may try opening your MTZ with a Hex editor to see if its structure looks fine. A Hex editor: http://www.flexhex.com/download/ (A very helpful feature of this software is that when you mouse-over a highlighted selection, it converts HEX numbers to DEC int or float.) MTZ file is not very complicated. After a simple header saying “MTZ” and a number (multiply the int number at byte 5-8 by 4 you get the position of the header information), a marker and a few lines of 00, the main body of an MTZ is a simple data array with each data points occupying 4 bytes (a floating point number REAL*4). Then after this block of data, the “header information” (not the head of the file) are stored at the end of the file, starting with “VERS MTZ”. In the data array block, since every line of data you see in view HKL starts with the H K L, you can easily locate the reflexion of interest by looking for the three simpler-looking numbers. For example: 00 00 18 c2 is –38, 00 00 00 00 is 0, 00 00 a0 40 is 5, So these are H K L –38 0 5 You may also see a lot of ff fa 5a 5a in the data block. Those are unmeasured data I believe. If you open your MTZ and cannot find the header information at the end then that means the file has lost a chunk. If you multiply the number stored at byte 5-8 by 4 and at that address you do not see “VERS MTZ”, the files also has changed length, or has been partially overwritten after being deleted. For example, If you have 1B BC 07 00 at byte 5-8, that’s Hex 0007BC1B=506907, multiply by 4 you get 2027628=1EF06C. Go to address 1EF06C, the cursor should land on the M of “VERS MTZ”. You can find descriptions of the MTZ format here: http://www.ccp4.ac.uk/html/mtzformat.html Zhijie From: Smith Lee Sent: Thursday, March 05, 2015 3:46 AM To: Zhijie Li Subject: Re: [ccp4bb] how to recover my data Zhijie, Is any mtz editor? I remember there is a software on it but I currently forget the name of that software. Smith On Thursday, March 5, 2015 6:23 PM, Zhijie Li <zhijie...@utoronto.ca> wrote: Hi Smith, I wonder why after you copy and paste the content of PDB it became readable by Coot. It is possible that some sort of reading error was introduced to the PDB file during the recovery, which was then filtered out by the text editors (extended ASCII for example). What was the cause of the damage? Can you send me the PDB file that coot could not open? For the mtz files, it can be quite difficult to fix if there was a reading error during the recovery. Being binary certainly makes it difficult to be dealt with. If you still have the .sca files (if you used HKL2000) maybe starting from there is easier. Zhijie From: Smith Lee Sent: Thursday, March 05, 2015 12:36 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] how to recover my data Dear All, Recently my computer hardware has been broken and all the data has been recovered to movable hardware by technician. However I find the recovered PDB file and the MTZcould not be openned by Coot. Then I open the revovered PDB file by WordPad, and from WordPad I copied it to notepad and save it as pdb file. I find the Coot can open the notepad saved pdb file, thus my pdb files can be succesfully recovered from the hardware. But will you please tell me how to have Coot open my mtz file? After data recovery by the technicial, the data size of the mtz file did not decrease, thus I think there is a way to have it recovered. I have not noticed there were similar or identical posts as mine for recovery data before in the CCP4 mail list. Thus I am looking forward to getting a reply from you on how to recover my mtz file. Smith
