The Aim of ThisThe aim of this is to generate the observed and calculated peak positions for the INEL PSD calibration file which can then be used to convert data files en-masse using Diffconv.
ConTEXT Freeware Text Editor Ultra Edit Shareware/Commercial ASCII text editors can do Column Editing!
ConTEXT Text Editor (toggle Control L for normal and column editing mode) (will also save to UNIX, DOS and Mac ASCII - "Tools, Convert Text to"): http://www.fixedsys.com/context/
The UltraEdit text editor for windows (http://www.ultraedit.com/) can do Column editing/cut/paste and this is the software to install if you wish to save hours cutting and pasting column data into the Diffconv *.pre calibration files.
Obtaining the "Calculated" Peak Positions
Normally the standards you use should have well defined Unit Cells (e.g., Silver Behenate and Cubic Y2O3 mixture) Information on Silver Behenate can be obtained on the Calibration standards for Powder Diffraction Page
Indx for Windows (part of the LMGP Suite) can be used to calculate peak positions to 4 (or more) decimal places if you give the cell constants (when you print the list to Wordpad, Indx prompts for the number of decimal places you wish to calculate to).
There is also a tutorial on Graphical unit cell refinement of the silver behenate C-axis using Celref. Celref can also help you identify HKLs if you get confused with this on your data (especially if you have spurious peaks or poor counting statistics).
Obtaining the "Observed" Peak Positions
NULL Conversion of the Binary INEL data to ASCII
In this case, a Silver Behenate and Cubic Y2O3 mixture is used for calibration
Select the Add Files to add the standard file you wish to convert to ASCII without using any calibration.
Select the list box to bring up the option to open GUFI files.
Now select the now enabled NULL Conversion option.
Select the options and output format and then Convert. You will be asked a few questions depending on the options you selected. Select a step size close to what is expected (0.03 for most INEL systems using GUFI files) and linear interpolation to constant steps has been found to do a decent and fast job.
NULL Converted Silver Behenate and Cubic Y2O3 standard data
The following shows why it can be good to use a Silver Behenate and Cubic Y2O3 mixture. Pretty much the entire range of two theta is covered. The following date is displayed in XFIT for Windows. (In reality, this data has been spliced together from two different samples though the theory is sound!)
Peak Profiling of the Converted Standard Data File
Use your favourite program to profile the obtain accurate "observed" peak positions from the standard data file.
There is also a tutorial on Empirical Peak Profiling of silver behenate using XFIT for Windows.
Editing the *.pre Diffconv Calibration File
Now use a column editor such as the ConTEXT Text Editor to edit a Diffconv *.pre calibration file. You can give this any name you want but it has to have the PRE file extension. (toggle Control L for normal and column editing mode)
The resulting file should look something like the following. You have to correctly tell it the number of data points. Also note that for the present version of the software you have to follow the tab delimited format of the *.pre file or diffconv will crash.
After doing all of this, you can now use the below calibration file to calibrate INEL data en-masse!
#y=Cx+K #Header K= 7.000000 C= 0.050000 #Observed Channel for the peaks, calculated 2-theta value for peaks #Calibrasion Data numOfDataPoints= 67 1.1961 1.5136 2.7202 3.0275 4.2508 4.5419 5.7651 6.0571 7.2737 7.5733 8.8470 9.0909 10.3675 10.6101 11.8702 12.1311 13.3801 13.6543 14.9761 15.1800 16.2769 16.7083 20.4154 20.4838 26.1620 29.1271 29.0488 31.5191 33.7135 33.7583 35.8731 35.8735 37.9036 37.8858 39.8594 39.8110 41.7293 41.6616 43.5596 43.4473 46.9894 46.8544 48.6161 48.4879 50.2290 50.0811 51.7295 51.6382 53.3126 53.1624 54.7949 54.6568 56.3011 56.1240 57.7153 57.5665 59.1330 58.9862 60.5518 60.3851 61.9268 61.7649 63.3063 63.1270 64.6448 64.4729 65.9748 65.8038 69.8722 69.7185 71.1569 71.0007 72.4107 72.2731 73.6755 73.5365 74.9316 74.7918 76.1582 76.0396 77.3934 77.2807 78.6216 78.5157 81.0665 80.9703 82.2895 82.1911 83.5126 83.4083 84.7045 84.6225 87.1150 87.0443 89.5118 89.4608 90.7046 90.6684 91.8962 91.8763 93.0900 93.0850 94.3118 94.2951 95.4986 95.5072 96.7078 96.7217 97.9057 97.9392 99.1135 99.1604 101.5443 101.6160 102.7680 102.8517 103.9932 104.0935 105.2398 105.3421 106.4736 106.5981 108.9636 109.1359 110.2357 110.4192 112.8205 113.0192 114.1205 114.3378 115.4452 115.6703 116.7714 117.0179