MIRAS/SIRAS Approach
In this section it is described how to use the Grafical User Interface to set up a new MIRAS/SIRAS project. The user has to fill the following forms named:
The following buttons are used to set the default values or to apply the changes to the fields of the form. By clicking on quit button the project will be abandoned and the main window will be displayed. To access the next form, if some changes have been introduced, it is necessary to click on Apply.
In this form some information are displayed such as
the
Configuration directory, the
User working directory and the Project name.
The user can supply a Job title for this project.
This form is used to get all the information from an MTZ
file. Once browsed, it is possible to view a short summary of the MTZ file.
For ab-initio only F and Sigma(F) are necessary; these two columns must be added
from available columns.
If necessary it is possible to specify a different space group. The user can just write the new symbol or to select it from a list.
On the bottom of this form information about symmetry and reflections is
diplayed.
This form is used to supply the cell
content. It is possible to specify the number of molecules in asymmetric unit.
The chemical content can be specified trough the weight or the number of
residues or the sequence (in FASTA format);
the sequence can be stored in a file or pasted directly in the right part of the
form.
Atoms external to the residues (ligands, heavy atoms, ...) should be added to
make the structure solution simpler.
Some useful information is shown in the output window at the bottom of the form.
The strategy for the structure solution is defined in this form.
The recommended procedure is the Patterson one as
alternative to Tangent Formula. It is possible to
define the number of trials divided in a number of blocks. Anyway robust
defaults are supplied.
If non-atomic resolution data are available, it is possible to generate and use
extrapolated reflections to increase the power of the algorithms to solve the
structure.
It is also possible to use extrapolated reflections for final map improving only.
By clicking on Apply button, the ab-initio straucture solution process will start.