some questions about optimizing

[xiaoling]

hello
   I encounter some troubles when I run the two-probe system in atk.I think we must optimize the system first , but I see the manu where it create the script --it not only includes the optimized sentenses but has some parameters such as brillouizone , basis set and so on . I want to ask what relations between these parameters  with optimizing process .Is it useful when optimized ?
  And I want to know if I want to optimize the two probe system and then caculate the transmission coeffcients,  must I  create two scripts seperatly and run twice ?
  Thanks very much for your help.

[zh]

The procedure for the geometry optimization of two-probe system has been outlined in the manual:
http://quantumwise.com/documents/manuals/ATK-2008.10/chap.optimizingtwoprobe.html. Please refer to them first. In addition, more discussion on the geometry optimization of a two-probe system can be found in previous thread:
http://quantumwise.com/forum/index.php?topic=283.0

Indeed, one can not optimize straightly the geometry structure of two-probe system. Alternatively, it is recommended to optimize the geometry structure of the equivalent bulk system. Therefore, the answer for your last question is yes.

[xiaoling]

 I will read the manual carefully. Thanks again.

[xiaoling]

 hello


Now I want to optimize the bulk system .Is it the same to optimize the two-probe system?
 

[zh]

The equivalent bulk system of a two-probe system is indeed a bulk system. Using VNL, you can easily specify the parameter for optimizing the atomic coordinates of molecule or bulk system.