CeO2 refinement information:

Space group:			Fm-3m
lattice a,b,c:			5.41 Angstroms
lattice alpha,beta,gamma:	90 degrees

fract. coordinates:	Ce	(0.00,0.00,0.00)
				O	(0.25,0.25,0.25)
Uiso: all			0.005
Qmax:				24.5 Inv. Angstroms.
Qdamp:			0.045

Data: CeO2 X-ray data at 300K for bulk and nano sample, collected at X17B3 beamline of NSLS using PerkinElmer IP detector

GOAL: Illustration of refining bulk and nanoparticle data of a system with "simple" structure. The nanoparticles are assumed to be spherical in shape.

TASKS:
1) Set up a model and perform refinement on bulk CeO2 data
2) Observe refinement results
3) Using the same setup as in 1), with same number of refinable parameters, attempt to execute a fit on data for nano CeO2 sample
4) Observe if the fit is successful. If not, why not? How the fit fails?
5) Introduce an additional parameter, nanoparticle diameter, and repeat the refinement
6) Is the refinement more successful?
7) Observe the value of the refined nanoparticle diameter. Observe the fit. Are the data completely explained by the model? If not, think of possible reasons why that may be the case.
8) Compare the refinement quality, as well as the values of refined parameters for bulk and nano data. How do they compare? Can you derive any conclusions from this comparison?
9) In addition to experimental PDFs, raw diffraction data are provided in form of .chi files (ascii format). Using your favorite plotting program, compare the two, and observe qualitatively the differences. Think of the consequences of particle size for observed diffraction data and corresponding PDFs.
10) What is the benefit of collecting data for both NP sample and corresponding bulk reference (when available)?