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--- x [2009/08/27 11:21] – clare
+++ x [2025/09/19 15:18] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
+====== x ======
+**[//x_calculation_step// !E]**
+Calculation step used in the generation of phase peaks and //fit_obj//’s. Peak_Calculation_Step is the actual step size used, it is defined is as follows:
+For and x-axis with equal steps and //x_calculation_step// not defined then
+Peak_Calculation_Step =  “Observed data step size” / //convolution_step//
+otherwise
+Peak_Calculation_Step =  //x_calculation_step// / //convolution_step//
+//x_calculation_step c//an be a function of Xo and Th. In some situations it may be computationally efficient to write //x_calculation_step// in terms of the function Yobs_dx_at and the reserved parameter Xo. It is also mandatory to define //x_calculation_step// for data with unequal x-axis steps %%(*%%.xy or *.xye data files). Example uses of //x_calculation_step// is as follows:
+x_calculation_step .01
+x_calculation_step = .02 (1 + Tan(Th));
+x_calculation_step = Yobs_dx_at(Xo);
+**[//xdd// $file %%[{%% $data }] [//range// #] [//xye_format//] [//gsas_format//] [//fullprof_format//] ]...**
+Defines the start of //xdd// dependent keywords and the file containing the observed data.
+{$data} allow for insertion of ASCII data directly into the INP file.
+//range// applies to Bruker AXS *.RAW data files; in multi-range files it defines the range to be refined with the first range starting at 1. //range// is set to 1 by default.
+xye_format (see section 10 as well) signals the loading of columns of x, y and error values; additional columns are ignored. gsas_format and fullprof_format signals the loading of GSAS and FullProf file formats.
+The following instruction will refine on the first range in the data file pbso4.raw:
+xdd pbso4.raw
+To following will refine on the third range:
+xdd pbso4.raw range 3
+To read data directly from an INP file, the following can be used:
+xdd {
+1 10  ' start, step and finish (equidistant data)
+2 3 4 5 6 7 8 9 10
+}
+// //
+xdd {
+_xy ' switch indicating x-y format
+.1 1   0.2 2   ...
+}
+**[//xdd_out// $file [//append//] ]...**
+Used for writing //xdd// dependent details to file. The //[[#k045|out_eqn]]// can contain the reserved parameter names of X, Yobs, Ycalc and SigmaYobs. See the keyword //out// for a description of //out_record//. The Out_Yobs_Ycalc_and_Difference macro is a good example of using //xdd_out//.
+**[//xdd_scr//  $file] …**
+**[//dont_merge_equivalent_reflections//]**
+**[//dont_merge_Friedel_pairs//]**
+**[//ignore_differences_in_Friedel_pairs//]  **
+**[//str//]…**
+**[//auto_scale// !E] **
+**[//i_on_error_ratio_tolerance// #]**
+**[//num_highest_I_values_to_keep// #num]**
+//xdd_scr//defines single crystal data from the file $file. The file can have extensions of *.HKL for ShelX HKL4 format or *.SCR for SCR format. All //xdd// and //str// keywords that are not dependent on powder data can be used by //xdd_scr// and //hkl_Is_from_hkl4//. Single crystal data is internally stored in 2q versus F<sub>o</sub><sup>2</sup> format. This means that a //lam// definition is necessary and the keywords //start_X//, //finish_X// and //exclude// can be used with //xdd_scr.//
+//dont_merge_equivalent_reflections// unmerges equivalent reflections, see also section 7.3.3.
+//dont_merge_Friedel_pairs// prevents the merging of Friedel pairs.
+//ignore_differences_in_Friedel_pairs// forces the use of Eq. (7‑12) for calculating F<sup>2</sup>.
+//auto_scale// rewrites  the //scale// parameter in terms of F<sup>2</sup>. This eliminates the need for the //scale// parameter. The value determined for //auto_scale// is updated at the end of refinement.
+//i_on_error_ratio_tolerance// filters out hkl’s that does not meet the condition:
+%%|%%F<sub>o</sub>%%|%%  >   i_on_error_ratio_tolerance |Sigma(F<sub>o</sub>)|
+//num_highest_I_values_to_keep r//emoves all hkl’s except for //#//num hkl’s with the highest F<sub>o</sub> values.
+An example input segment for single crystal data refinement is as follows:
+xdd_scr ylidm.hkl
+MoKa2(0.001)
+finish_X 35
+weighting = 1 / (Sin(X Deg / 2) Max(1, Yobs));
+STR(P212121)
+   a  5.9636
+   b  9.0390
+   c 18.3955
+   scale @ 1.6039731906
+   i_on_error_ratio_tolerance 4
+   site S1  x @ 0.8090  y @ 0.1805  z @ 0.7402  occ S 1  beq 2
+   site O1  x @ 0.0901  y @ 0.8151  z @ 0.2234  occ O 1  beq 2
+   ...
+The SCR format is white space delimited and consists of entries of h, k, l, m, d, 2q, F<sub>o</sub><sup>2</sup> which is the format outputted by the Create_hklm_d_Th2_Ip_file macro.
+**[//xo_Is//]...**
+**[//xo// E  //I// E]...**
+Defines a phase type that uses x-axis space for generating peak positions, see example XOIS.INP. //xo// corresponds to the peak position and //I// is the intensity parameter before applying any //scale_pks// equations.