This page introduces ENDEAVOUR's so-called 'Structure Solution Wizard'
for the easy preparation of the structure solution process:
Step 1 of 7 - Define cell parameters and space group
Cell parameters must be known, i.e. the powder data must be indexed,
whereas the knowledge of the correct space group is not essential.
The calculation can always be performed in P1 and the correct space group
can be determined afterwards. However, if the space group is known, the calculation speed is much higher.
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Step 2 of 7 - Define molecules (optional)
Endeavour supports the usage of molecules with flexible torsion angles
as well as rigid-body fragments if they do not lie on special positions of the spacegroup.
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Step 3 of 7 - Define atoms in unit cell
Enter the unit cell contents, i.e. the formula sum and the number of formula
units per unit cell for single atoms, i.e. atoms which do not belong to molecules.
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Step 4 of 7 - Define the diffraction data
The next wizard page is dedicated to the input of the diffraction data.
You can open the prepared file containing the diffraction data as a list
of 2 theta- and corresponding intensity values, or, as in this case,
a list of |F|(hkl) data.
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Step 5 of 7 - Define settings for potential
This page is dedicated to the input of data needed for the calculation
of the potential energy. There are two possible funtions which may be
used, the 'simple repulsion potential' and the 'Lennard-Jones potential'.
Both potentials need empirical parameters. Endeavour has been designed
carefully to especially make the generation of potential parameters as
simple as possible.
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Step 6 of 7 - Define optimization settings
This page offers some options concerning the optimization. For instance,
the so-called 'cost function balance' may be adjusted, i.e. the contribution
of either of the two parts of the cost function to the overall value.
Thus, weak diffraction data may to a certain degree be balanced by a high
quality potential and vice versa.
Besides this, the speed of the calculation is controlled by the slider
'optimization speed' that could take any integer value from 1 to 10.
A value of 10 means highest optimization speed, however, because of the
underlying simulated annealing optimization method, also lowest success
probability.
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Step 7 of 7 - Define environment settings
Since Endeavour is not only a program for structure solution but also for
structure visualization, you can view the intermediate structures during the
structure solution process. On wizard page 7 you can tell the program how this
should be done.
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