...quite a strange question I would say.. sounds like some assignment to a student.

Nobody with any experience in crystallography would ask this question, and anybody working in XRD would do a search match first (to be sure somebody hasn't already found the solution), an indexing using the traditional tools (e.g. the freely available crysfire suite) and or a test with direct methods (e.g. using one of the software of the Giacovazzo group such as EXPO)

Thank you all.

You're right. I'm a student who is not much familiar about XRD. I tried to find out hkl values. But c/a value calculated is found to be wrong. Can we use the same method for tetragonal and hexagonal? I'm not much sure about this.

Do you know the crystal structure of your sample?

If you that that, it might be easy way to go for the next step.

Why you say the c/a is wrong? If you calculated it, then you extracted the cell parameters and therefore you have already indexed the pattern!

We have already given c,a values. We have to find it using peak values and have to check whether it is right or not.

sorry (Matteo Leoni)! to index manually XRD peaks of tetragonal and hexagonal is not joke! one can index after lot of hardworking no matter who he/she are, whether a student or teacher......thanks to auto indexing programming which have solved the problem of indexing the xrd pattern of substances with no time. However one must know about manual indexing. i have solved hexagonal manual indexing problem but still tetragonal indexing posing problem for me. If any body has worked problem then please share no software only manual worked problem. Thanks.

Here I am attaching a lecture on Indexing powder diffraction data using FullProf of FPSchool 2013. I hope it will be helpful to all.  

Dear Aga Shahee

Have a nice time

Please, can you attach a clear XRD-chart?

Thank you in advance

Dear Ahmed Saeed Hassanien

Thank you for your good wishes and wish you too a very nice time.

Sorry to say, I am not able to understand your message of attaching a clear XRD chat. Please elaborate your message. 

Should I present the index chart for a tetragonal phase using FullProf?

waiting for your message

Thank you again.

Dear Aga Shahee

I wish for you have happy times

Thank you for replying and your kind comment. You are welcome. I would like to ask you to re-share the file of the Indexing powder diffraction data using FullProf but with a fine resolution, where the previous is not clear. In addition the the index chart for a tetragonal phase using FullProf and any other related materials, If possible.

Thank you very much.

God bless you,

yours,

Ahmed Saeed Hassanien

[email protected]

Dear Ahmed Saeed Hassanien

Here I am uploading a video created by me to find lattice constants, Indexing and profile fitting of powder diffraction data of unknown phase ( e.g.Tetragonal BaTiO3) using FullProf. I hope it will be helpful to all of you.

Youtube link (https://youtu.be/2SzIfWxYNDs)

with regards

Aga Shahee

Here you may find to calculate manually

https://www.banglajol.info/index.php/JSR/article/download/11578/10443

Do cite this article if you find it helpful.....

If you are aware of the crystal structure of your sample, then you may check the JCPDS file and match your peaks with that of the JCPDS file, which will provide you the required values of (hkl).

Dear Thambi,

Please follow these steps:

1. Search CIF of your material from any database (and keep the reference)

2. Use VESTA and drag the CIF.

3. Simulate the XRD data using the powder XRD diffraction tool

4. Compare with your data

I have been using it to ease my work. But sometimes, I use databases. Both methods can be combined to ease our work on XRD data.

Regards,

S. Muhammady

Firstly we must know the structure, formula and the plot your data in origin to find the 2theta value starting from characteristic peak, find theta. Find sin( Theta) Then its square. then sin(theta)/square of sin(theta) i mean ratio, u will get a number where maximum times u need rounding of figures. Then set the hkl values as per formula.

for eg if 2theta is 44.76, theta will be22.38 , sin22.38 is 0.38 and square of sin22.38 is 0.14. Now ratio will be 4 and hkl vales can be set as 200