====== OpenMX ======
[[hhttp://www.openmx-square.org/|OpenMX]] is open source software that calculates perform density functional theory (DFT) calculations for your class project. You will use it to calculate band structures in this course.  OpenMX is installed on the computers in Weniger 412 and you can access from there or you can ssh in remotely from your own computer.  Mitchell Senger has written a wonderful {{:openmx_tutorial_ph575_w2019_20190315.pdf|tutorial}} to help you get started. After completing Mitchell's tutorial, you will have produced your first band structure calculation.  Once you have completed one example, you'll can find additional information and tutorials on the [[http://www.openmx-square.org/openmx_man3.8/openmx.html|OpenMX user manual]] on the OpenMX website. 

For calculations for your own material, you will need the position of the atoms in your material. The Crystallography Open Database is one good place to look for crystallography information files (.cif files). A great way to visualize the information in a .cif file is to drag the .cif file into the browser-based OpenMX Viewer. Chrome is the recommended browser for OpenMX Viewer.

For you own calculations, you will need to choose an appropriate path through k-space. This Brillouin zone database is a useful resource. The wikipedia article about Brillouin zones is also helpful for visualizing your path.

====== Computers in Weniger 412 ======
 The computers in Weniger 412 were reconfigured over summer 2018 so that you now log in with your onid credentials. If you are in the computer room using the terminals, you may use any computer, and your results will be in your home directory regardless of which computer you use. 

We will, however, assign you a particular computer and request that you use that machine when you log in remotely.  This will prevent unintentional overload of the system. 

==== Linux ====
There are about 24 terminals in Weniger 412, running Linux. The graphical interface is called Nautilus - it looks a bit like Windows. OpenMX runs in command line mode, though, so you will need some rudimentary unix knowledge.  Mitchell's tutorial is helpful. (There are lots of UNIX tutorials on the web.  Here are simple ones from Rubin Landau of OSU Physics http://www.physics.oregonstate.edu/~rubin/nacphy/UNIX/ and from the University of Surrey:  http://www.ee.surrey.ac.uk/Teaching/Unix/). 

Here are some very basic unix commands:

| ''pwd''    | **p**rint **w**orking **d**irectory  (tells where you currently are)   | 
| ''ls''    | **l**i**s**t files in the working (current) directory |
| ''ls -l''    | **l**i**s**t **l**ong form of files in the working directory     | 
|''cd TiC''| **c**hange **d**irectory to the one named "TiC"|
|''cd ..''| **c**hange **d**irectory to a level up from the current one|
|''rm myfile''|**r**e**m**ove the file named "myfile" from the the working directory. Remember there is no recycling bin, so be careful|
|''cp myfile /home/ph575_nn/TiC'' | **c**o**p**y ''myfile'' in the current directory to a directory called ''/home/ph575_nn/TiC''. |
|''mkdir Docs'' | **m**a**k**e a **dir**ectory called ''Docs'' |
|''ps -u janet'' | list all **p**roces**s**es being run by **u**ser **janet** (displays a number XXXX with each) |
|''kill XXXX'' | **kill** the process identified by the number XXXX |

==== Words of wisdom from previous classes ====
  * You transfer files from the OpenMX environment to your personal computer through email. You can access the internet by running 'chromiumbrowser' in the terminal window and email the files as you would normally.