Structure output to cif incorrect

GULP
1

Hi, I’m having issues with the .cif file output from GULP. The program will happily dump a cif file in, what appears to be, the correct formatting. However, when I go to visualise the structure in Mercury the structure appears squashed, as if the symmetry and/or lattice parameters are incorrectly described:

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Capture3995×481 150 KB

It seems that the space group is correctly identified but the lattice parameters are for the primitive cell rather than the crystallographic (non-primitive) cell. I have somewhat been able to circumvent the problem by manually editing the lattice parameters to the non-primitive cell but I am still missing half of my structure, see below.

Output cif from gulp, with manually adjusted lattice parameters:

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Capture4811×690 89.1 KB

Input structure, before reading into gulp:

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Capture5801×705 167 KB

How can I fix this? Thanks so much in advance!

2

I’m guessing that you’re using an older version of GULP here? In version 6.3 there should be a modification to output the centred cell to make things easier for viewing in some codes. Otherwise if you use Materials Studio or GDis then you can view the GULP output/restart files directly.

3

I had identical issue with GULP 6.2. The issue is handled in 6.3. I belive GULP internaly converts centered cells to primitive for performance reason. And during the export to cif the back-conversion to centered description was not done in 6.2 …

4

Ah I see, I do believe that is the case - thank you. I will update to 6.3 and check that resolves the issue…