Now I have to put on my hat as Chair of the ICDD... Please note that the PDF is a copyrighted product sold and licensed for use for a certain period. The 2002 and 2004 versions mentioned by @Sasan Rostani, besides being obsolete, should therefore not be present in the computer and not be used, as they violate the terms of sale/use. I think you would not be happy if somebody would keep coming to your place to get a free lunch every day if you just invited that somebody once, right? When you use a product but you don't have the legal right of using it, you are the one eating that free lunch. So if you use the PDF database as a tool for your research, please buy it. A good diffractometer with no extra tools is like a great racing car with no engine. Unfortunately the common belief is that only the hardware should be paid for.. @Robert Möckel, maintaining the PDF4+ database license in a laboratory has the cost of 1-2 US coffee a day... or less than the cost of sending one lab member to a conference.. it all depends on how you see things..

To get back to the original issue, i still believe the question is not clear and the answers suggesting to randomly try this and that supposing one situation or another clearly confirm this. As I have already said multiple times, every time we suggest something here, we should think that if we would be surgeons we might be suggesting somebody to take a scalpel and start cutting..

My humble suggestion is to get a clear vision first and avoid the amateur approach Fortunately medicine is not this field.. cause there would be a lot of dead patients here, guys...

PS. As a side note, the ICDD PDf4+ database contains all relevant ICSD entries (including the structure data), so if you don't find a match in the PDF, I doubt you can find it in the ICSD.

Dear Anchali,

Try to do Rietveld refinement of your data with parent material parameters using the software JANA 2006 or Fullprof. You can also match your data on the ICSD site by following the link:

http://icsd.kisti.re.kr/icsd/icsd_chemistry.jsp

Thank you

Dear Anchali, your question is a bit confuse.

You have absolutely no match? Which database do you use? You synthesized a known compound and you can't find it in the database?

Remember that the search match works by trying to find a match for the observed pattern (peak positions and possibly intensities) in the reference database. If you find no match then either the compound is new or it's known, but not present in the database. So please better specify what's the issue if you want to receive some meaningful answer

BTW Harshit Agarwal , Highscore Plus can do Rietveld refinement.. but what do you refine if you don't have a structure in the first instance? Moreover if somebody has already troubles with a search match, I doubt he'd be confident to perform a more complex task such as a Rietveld refinement...

Matteo Leoni Kindly Try to understand the words of me and Anchali. She is matching her XRD data using in X'pert high score for which I have suggested to check on ICSD site. Regarding to Rietveld, I am familiar with X'pert high score, but the quality wise FullProf and JANA is much better and powerful than that.

Thank you for your suggestion.

Thank you Harshit Aggarwal, I will try your method and hope I get my result.

and Matteo Leoni, I have absolutely no match, my compound is less known and I am not able to find in xperthigh score database (i.e. ICSD database).

Plz check your database. If it is showing no result, most probably database is corrupt. Such type of problem does not come with Xpert highscore. Which database you are using, PDF-2 or PDF-4? Can you please let me know 2θ value of your highest intensity peak. And you cannot do rietveld refinement in such condition.

Doriana Vinci

In my first comment on this question, I have mentioned a line "try to do Rietveld refinement of your data with parent material parameters" which means If you have synthesized a material by doping or replacing the site of a material, and you don't know the parameters of that material, then take the reference parameters of parent material which is already known and then try to refine the XRD data.

As you have AB2O4 type system and by doping or replacing the A site with another element for which there is no report then try to use the parameters of known AB2O4 system.

If still it is completely new material, try to find the lattice parameter using Dicvol, Treor and ITO's method.

Mostly X'pert high score has limited data for checking the XRD reference pattern that's why I have suggested to check the XRD on the ICSD site which is,

http://icsd.kisti.re.kr/icsd/icsd_chemistry.jsp

If still you have any doubt and query, kindly write me anytime.

Thank you

Dear Doriana,

You should use different databases such as pdf 2004,pdf 2002 and ICDD.

Every database has variety references code for identity compounds.

Doriana Vinci

Yes dear, you are right. I am agree with you.

My suggestion towards your completely new structure is as follows:

Try to calculate the lattice parameter first manually for profile fitting. Now using your expected stoichiometry of elements, Try to draw an expected model of material in PCW software and model the XRD pattern. For the valance state of elements present in the material you can do XPS. After the modelling, try to refine the structure using P1 symmetry first.

If you are working on Inorganic materials, then I can help you in modelling of your unknown structure, but it will take time.

Thank you

Harshit

Doriana Vinci you have to buy it from the ICDD ( http://www.icdd.com/ ) but it's quite expensive. There is also a free alternative: COD (http://www.crystallography.net/cod/) which is OK, but not as comprehensive as the pdf-database, unfortunatelly.

Now I have to put on my hat as Chair of the ICDD... Please note that the PDF is a copyrighted product sold and licensed for use for a certain period. The 2002 and 2004 versions mentioned by @Sasan Rostani, besides being obsolete, should therefore not be present in the computer and not be used, as they violate the terms of sale/use. I think you would not be happy if somebody would keep coming to your place to get a free lunch every day if you just invited that somebody once, right? When you use a product but you don't have the legal right of using it, you are the one eating that free lunch. So if you use the PDF database as a tool for your research, please buy it. A good diffractometer with no extra tools is like a great racing car with no engine. Unfortunately the common belief is that only the hardware should be paid for.. @Robert Möckel, maintaining the PDF4+ database license in a laboratory has the cost of 1-2 US coffee a day... or less than the cost of sending one lab member to a conference.. it all depends on how you see things..

To get back to the original issue, i still believe the question is not clear and the answers suggesting to randomly try this and that supposing one situation or another clearly confirm this. As I have already said multiple times, every time we suggest something here, we should think that if we would be surgeons we might be suggesting somebody to take a scalpel and start cutting..

My humble suggestion is to get a clear vision first and avoid the amateur approach Fortunately medicine is not this field.. cause there would be a lot of dead patients here, guys...

PS. As a side note, the ICDD PDf4+ database contains all relevant ICSD entries (including the structure data), so if you don't find a match in the PDF, I doubt you can find it in the ICSD.

I have PDF2004

And I would like to shear it with you but How?

Thanks to all for your suggestions and advice. As I am new to this field ,I will do step by step instructions as suggested by all of you and keep in mind for future use. Thanks again for all your help and time.

Sasan Rostami: perhaps I should be more explicit on this, as it seems the message was not clear enough: using or sharing the PDF2004 database is a CRIME.

I met such situation when I synthesized CdGeAs2 about three years ago. XRD data we recieved did not correspond to new XRD data base. I applied to USA people and Prof. Robert Feigelson sent me the new data which were obtain by Russian scientst so about 2004 year. These true data are still not in database. Our data were in very good agreement with data of the Russian scientist. Maybe your situation is similar....

Thank you Gallina A Verozubova and Robert J Koch. I was new to that field at that time. That is why I got confused. With the help of above answer I will able to get solution to my problem.

Just some addition to Robert Koch: Work with your chemical and crystallographic knowledge and with literature about the phases present in your chemical system (and get the crystallographic data). Use of ICDD search match can be quite practical (but it is a crude tool, this is not science; sorry Matteo), but it is not the only way to resolve what is in your specimen based on powder-XRD data. If you naively use database search-match routine without own critical thinking (and perhaps with imapproriate setting) you nevertheless can get meaningless results (I have seen this frequently in the literature). Maybe your lab responsible person can also teach you something.