Dear M. Pavithrakumar ,

I guess your problem is to find a reliable warning-free CIF for the system of your interest.

There is no correct CIF file from any phase in practice. There are CIF files available without syntax errors, reliable to be used. Any CIF file will account for stress, distortions, isomorphic substitutions, interstitials, among other effects. Anyone similar structure will be exactly as yours. So, they are only start point references.

In general, all of them have passed in a previous check routine before publication.

All reliable and good practice periodic have the obligatory checking CIF files before acceptance.

Remember, the published CIF files are experimental. Therefore, may have or not specific effects that do not affect your particular sample.

Having all in mind, I suggest the COD (Crystallographic Open Database - http://www.crystallography.net/cod/) and the American Mineralogist Databank (AMD) - http://rruff.geo.arizona.edu/AMS/amcsd.php.

Those are free of charge.

Proprietary CIF databases are CCDC, previous JCPDF, ICSD. Check your Institution's access to those databanks.

The perovskite structure is a reference one. Several published CIF files in AMD may be used as a reference starting structure.

Best regards,

WNM

Dear M. Pavithrakumar thank you for sharing this very interesting technical question with the RG community. The study of halide-based tin and lead perovskites has become a highly popular and important research topic in recent years. You can find the CIF files for the MASnI3 perovskite structure (MA = methylammonium) in the Supplementary Information of the following relevant article:

Negative Thermal Quenching in FASnI3 Perovskite Single Crystals and Thin Films

Article Negative Thermal Quenching in FASnI 3 Perovskite Single Crys...

Luckily the full text of this article has been posted by the authors as public full text on RG. Thus you can freely download the original article as well as the Supplementary Information as pdf files. The Supplementary Information contains the following data (citation):

• Experimental details and additional data computational approach and calculations, white-light microscopy image of single crystals, projected density of states and calculated values for band gap and effective masses, and additional spectroscopic results on thin films and single crystals (PDF)
• Crystallographic information file of FASnI3 taken at 298 K (CIF)
• Crystallographic information file of FASnI3 taken at 200 K (CIF)
• Crystallographic information file of FASnI3 taken at 100 K (CIF)

Just click on the following link to access the CIF's:

https://pubs.acs.org/doi/10.1021/acsenergylett.0c01166?goto=supporting-info

I hope this helps answering your question. Good luck with your work and best wishes, Frank Edelmann

Thank you very much, professor Frank T. Edelmann, for your informative answer. We planned to investigate the structure and electronic properties of the passivated lead-free perovskite material. we already completed a few studies based on lead materials. I have FASnI3 cif already. At present my material of interest is MAPbI3 so I am looking for that.

I found few reported MAPbI3 structures from the following literature:

Article Structure, optical and electrical properties of CH 3 NH 3 Sn...

by using the JCPDF number I have downloaded the following set of cif file.

my question now is, whether the cif which I have downloaded is a sufficient one to proceed with my work?.

Dear M. Pavithrakumar I'm actually not a proven expert in this field. However, I assume that if you downloaded a published / deposited CIF file for MAPbI3 it should be be fine for proceeding with your own work.

Good luck and best wishes, Frank Edelmann

Dear M. Pavithrakumar , you may find all the desired information in the masterpiece publication of Constantinos Stoumpos and coworkers in Inorganic Chemistry 52 (2013) 9019, and the electronic supplement of this nice work, which I can really recommend to study in detail. Hope this helps, Dirk