TDFw Manual

The program has a menu, speed buttons and four tabs.



 Button   Action
 creates a default data template
 loads selected data file
 writes current data (including fitting results) into a file
 prints a hard copy of the data
 font selection
 prints the fitting curves
 checks data validity
 initial calculation
 single fitting iteration
 multiple iterations  *)

*) Multiple iterations - uses values from the Results Tab: Stops if number of iterations exceeds IterMax, the mean square deviation becomes less then dPPM, or energy step becomes smaller than dEmin

 This bar also contains the One-level Fit checkbox - Curie fit if checked, Two-level fit if unchecked.


Info tab

This tab contains the program title and contact information.  


Input tab

The experimental data can be loaded from a file or entered manually.

Loading data from file

To load data go to "File", "Open" and select a file. The standard extension is *.tdf. Actually the TDF-files are plain text files and can be created or modified using any text processor. The file structure is described below. The contents of the input file are displayed in the "Input" tab.

Manual input

The "Input" tab can be also used for manual input. 

 NExperim - NParam: Data Redundancy is determined automatically in calculations (Must be > 0).

 Data exclusion

Sometimes it is necessary to remove the entire row or column in the data grid (usually due to the low accuracy of measurement). This can be done by Shift-clicking (rows) or Ctrl-clicking (columns). The excluded rows and columns are marked as "X":

The values are not actually deleted, they are just not used in the fitting procedure. They can be undeleted by Shift/Ctrl clicking again. In the above example the 3rd point and the line "b" are excluded. In the output file (see the section below) the deleted values are labeled with zero weights:

Weight factors:
         Line 1 Line 2 Line 3 Line 4
Point 1      1      0      1      1
Point 2      1      0      1      1
Point 3      1      0      1      1
Point 4      0      0      0      0
Point 5      1      0      1      1


Fitting tab

After loading data from a file or manually entering data it is recommended to check data validity by pressing

For the calculation of initial quantities press

After the initial calculation, the Fitting and Results tabs become available for editing.

After that the fitting can be performed in three ways:

  1. Semi-automatic fitting  . One iteration is performed by pressing this button. The values of mean square (standard)  deviation, the energy gap and the energy step are displayed for controlling iterations.
  2. Multiple iterations . This regime uses values from the Results Tab: Stops if the number of iterations exceeds IterMax, the mean square deviation becomes less then dPPM or energy step becomes smaller than dEmin.

  3. Manual fit.

    In the above example the energy step is (555.5 - 0.001)/100 = 5.55499 cm-1.


Results tab

This tab includes the following settings and final fitting results:


Recalculate: Calculations with new dipolar shifts.

Menu options


File format

The input file is a simple Text (ASCII) file. Each line contains data and an optional comment string in the end (displayed in red). The same format is used for output files. Below is a sample file.

Sample file

1  1 = Calculated, 0 = Not calculated
Curie Dependence Sample File
4  - Number of Lines
5  - Number of Temperature points
               a     |    b     |    c     |    d
           -496.8000  -496.8000  -496.8000  -496.8000   - Spin Factors
              0.0000     0.0000     0.0000     0.0000   - Dia Shifts
    3.4000  -30.0000   -26.6000   -24.8000   -27.7000   - 1000/T, Para Shifts, Point   1
    3.5700  -31.4000   -28.0000   -25.8000   -29.3000   - 1000/T, Para Shifts, Point   2
    3.9200  -35.4000   -31.1000   -28.1000   -32.9000   - 1000/T, Para Shifts, Point   3
    4.3300  -39.6000   -34.1000   -30.0000   -36.7000   - 1000/T, Para Shifts, Point   4
    4.8200  -44.6000   -37.6000   -32.2000   -41.3000   - 1000/T, Para Shifts, Point   5


  1. Version (currently 2).
  2. Calculation status: 1 = Calculated, 0 = Not calculated - distinguishes between the input and out files. The latter contain the fitting information at the end of the file. 
  3. Comment.
  4. Number of NMR lines.
  5. Number of temperature points (Number of experiments).
  6. Ground-state electronic spin. 
  7. Excited-state electronic spin.
  8. Line names separated by "|".
  9. Spin factors.
  10. Diamagnetic shifts (in this example diamagnetic shifts are already subtracted from all lines).
  11. 1000/T, Paramagnetic Shifts (Lines 11 to 15).

Remark 1: All comments (displayed in red) are optional and can be omitted.

Remark 2: All values should be separated by at least one space.


Output file

The output files contains the input information in the beginning (this means that output files can be used as input files also). 

Next, the output file contains the data from the Results tab.

After that, the fitting curves are recorded (1000/T, Paramagnetic Shifts - 51 equidistant points). They can be used in plotting programs.

The weight matrix is recorded at the end of output files.

Weight matrix

The weight matrix is 1 if the point was used in fitting or 0 if it was excluded.

Weight factors:
         Line 1 Line 2 Line 3 Line 4
Point 1      1      1      0      1
Point 2      1      1      0      1
Point 3      1      1      1      1
Point 4      1      1      1      1
Point 5      1      1      1      1

 In the above example the first two points of the third line were excluded (or are missing).


Back to Temperature Dependence of NMR

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©Nikolai V. Shokhirev, 2002-2004