First of all must base on the graph, how good the model to the observed data. Very noisy data can easily achieve GoF ~ 1, even in worse < 1 (bad model), Rexp and Rwp typicaly huge. Here I attach what is the R-factor according to Brian H Toby (GSAS). All of this statistic parameters much depend on nature of your sample, sample preparation, instrument settings and data collection strategy.

Special for structure solution; must have very high signal to backgroud ratio and peak to peak separation (monochromator (few bounches) or energy dispersive detector (

Thanks for the response. I have already read the article of Toby unfortunately NO clear idea of "final conclusion" associated with my questions. Many references found to be dealing with METAL OXIDES, and only one-two applied in transition metal complexes.

The followings are some examples of my "projects".

1.Complex 1; Monoclinic C2/c; a=25.206926 ; b = 13.540572; c=22.988400; V=7838.219727; Rp=2.95; Rwp= 6.26; Rexp= 1.63; GOF= 14.747; R-Bragg factor= 0.04

Please give me a commence.

2. Complex 2: Monoclinic C2/c; a = 13.662 Å, b = 23.040 Å, c = 29.268 Å, = 90°, β = 100.15°, = 90°, V = 9069.05 Å3, Rp = 5.5, and Rwp = 9.94 and Rexp = 2.68 leading to χ2 (GOF) value of 13.72. The goodness of the fitting might be also reflected by the derived Bragg R-Factor of 0.02. (This has been accepted in CMJS)

Please give me commence.

3. Complex 3: triclinic symmetry of space group P1, and lattice parameters of  a = 9.962012Å, b = 39.898914 Å, c = 17.191874 Å, = 95.929291°, β = 86.181854°, = 92.651680°, V = 6776.328613 Å3, Z= 4, Rp = 5.19   and Rwp = 10.65. Rexp = 1.99. The goodness of the fitting (GOF=28.58) was also reflected by the derived Bragg R-Factor of 0.03.

4. Complex 4. THIS is COMPLICATED result concerning GOF, though the fitting seems good.

space group P 21/M , and lattice parameters of  a = 9.865076   Å, b = 31.665224   Å, c = 17.698393Å, = 95.929291°, β = 83.768097°, V = 5495.951172   Å3, Z= 4, Rp = 3.31   and Rwp = 10.47. Rexp = 0.37. The goodness of the fitting (GOF=813.7) was also reflected by the derived Bragg R-Factor of 1.43.

Please give me a commence particularly for the Rexp and GOF

Thanks

If just by GoF, overall still far from accepted value.

Rwp < 0.15 a is good value for complex phase (monoclinic to triclinic) and if your Rexp ~0.1, GoF ~ 2.25. Rexp is the minimum value of Rwp by a certain number of refineable parameters.

When you perform difference fourier u still can see some peaks.

Would you change the Y-axis to log-scale?  Please post the instrument configuration and data collection information as well.

Dear Maykel Manawan

If I can not get the R's values u suggested do you think then the powder compound CAN NOT be refined by PXRD method to estimate the cell parameters?

Can u show me an EXAMPLE of the (powder) fitting of any complex compound?

Now I would like to show you NOT only the fitting BUT also the comparison TABLE of the cell parameters to the references FOUND in SINGLE CRYSTAL, Ref [16] and [4].

Then please give me comment

"If I can not get the R's values u suggested do you think then the powder compound CAN NOT be refined by PXRD method to estimate the cell parameters?" You can still do the structure solution but the model wont give better R-values if you perform rietveld analysis. Try to extract the difference map (DELF) as well. Actually I'm doubt about the Rwp, it's quite big even with intensity less than 5000, that's why i wanna see in log scale.

"Can u show me an EXAMPLE of the (powder) fitting of any complex compound?" I ever refined both protein powder and single crystal from synchrotron radiation but I cant provide the data nor post the picture because they're not belong to me. All I can tell I've got a curve fit and R-factors within that range.

I have already give you 4 samples of fitting including the last, please recheck again particularly for the NiPhen147.BMP above. Sorry, can you tel me how to convert the data in column Y to be in log scale and WHAT is the reason and the consequence?

Unfortunately I have no experience at all in nor heard DELF.

Thanks

Dear Sir. Usually there's an scale option in the software both x and y. Y options is linear, log, square etc. In log scale we can see more details; backround or small peaks. DELF is just a fourier difference map in GSAS, Rietan must have this function as well.

Dear Maykel M,

If we use log y, will we get different R's value? So can we directly convert to log y and then use the data for running Le Bail. If so I will do it soon. to see the fitting. Thanks

It wont change the R-values.