MOF structure is distroyed at end of simulation+ No saturation point in isotherm

Started by reshmajose, May 28, 2018, 10:12:34 AM

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reshmajose

Dear All,
I am beginner to RASPA software. I am basically working on a chromium based MOF and its O2 binging properties. But Cr-MOF is not provided in the RASPA library. I have optimized my MOF and taken those coordinates and gave input in RASPA but I am getting a straight line even at high pressure and  12 cutoff distance without no saturation at all. The experimental data is saturating around 8wt% so it seems my calculation is going wrong. Also at the end of simulation I am getting a totally destroyed structure compared to the one I have given as input. I am unable to solve both these problem.
Can anyone kindly help me to provide a correct input format so that the adsorption value can be obtained reasonably similar to the experimental data without losing my structure..
I am really stuck with my input file :-[ :-[ :-[
Kindly Please help me..

Thanks a lot
Reshma

David Dubbeldam

What do you mean with a "totally destroyed structure"? Are you using a flexible model? In that case you need a good force field to describe the flexibility of the framework.
For a rigid structure, the end and begin structure should of course be identical. In case you meant a rigid structure, then check whether the space-group is given correctly. You can always change your structure to a P1 structure, so that there are no space group issues.

reshmajose

Dear Sir,

Thanks a lot for your kind reply. I am using Chromium based MOF and is a RIGID MOF. I have optimized my structure and saved it in CIF format using Mercury software. But I do not know how to generate it with P1 symmetry. Sir can you kindly suggest me some software to get my structure in the required format of RASPA2-2.0.3
I have installed RASPA2-2.0.3 version.
Kindly tell me whether the RASPA version I installed is suitable for MOFs or not.

Thanking You,
Sincerely,
Reshma

Pezhman Zarabadi-Poor

Dear Reshma,

It's impossible to answer your question without knowing the inputs you are using for the simulations. The better way is providing structure file, force field files, and simulation.input.

Regarding the P1 structure, you may also try VESTA for this purpose.

My best,
Pezhman