Parametric refinement method [1] enables simple parallel refinements of large amount of XRPD datasets dependent on external variables. Parametric refinements are carried out by establishing non-physical models that control the convergence of refinement and physical models that describe the evolution of refinable variables with respect to the external factors (temperature, pressure, time, etc.)
Parametric refinement offers ample advantages over normal sequential refinements. Parameterization of variables stabilizes the refinements and improves the precision of refined parameters [1]. It also reduces the number of free variables and creates the possibility of refining non-crystallographic quantities.

As a first step towards parametric refinement a programme that automates the process of single phase sequential Le-Bail/ Pawley refinements has been developed and presented here. The programme interacts with Topas [2] (a powerful software suite for total powder pattern analysis) for carrying out sequential and /or parallel refinements. Topas’ macro language offers the flexibility to introduce user-defined constraint models in a very simple manner.

 To facilitate the automation of sequential phase refinements, a general method to determine the number of phases in in-situ XRPD data has been developed. In this method, the boundaries are determined by comparing the Pearson's correlation coefficients of the neighboring patterns.

 The sequential refinement routine and the phase boundaries determination routines are implemented as an interactive module in the multi pattern, data reduction software Powder 3D [3] with various options for manual interaction.

References
[1] G.W. Stinton and J.S.O. Evans, J. Appl. Cryst  40, 87–95 (2007)
[2] A.A. Coelho,  TOPAS, v4.0. Bruker AXS, (2007).
[3] B. Hinrichsena, R.E. Dinnebier, and M. Jansen, Z. Krist.,Supplement Issue 23 (EPDIC-9
      proceedings), 231-236 (2006)

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