Replacing Wien 2K

The purpose of this page is to solicit input/feedback from the students in Ph 575 on the use of Wien 2K as a teaching tool in Ph575. Please add/comment on the strength and weaknesses of Wien 2K and add/comment on proposed features of the new system (flair/gem) described below. Please mark your edits with your initials (JD) but you don't have to.

• web interface (both input/output) (gs)
  • almost no computer background necessary (gs)
• real research tool (gs)
  • potentially useful in your graduate/post-graduate research (many examples) (gs)
• shows the difficulties in doing research (gs)
• knows cif files

• limited access during project crunch time (gs)
  • see next point (not free)

• not free (gs)
  • can't use Wien 2K on your own computer (gs)
  • access restricted during graduate research (gs)
  • access requires license purchase during post-graduate research (gs)

• web interface not always easy or intuitive (gs)
  • if the defaults don't work you need to consult a very extensive handbook which was not written for beginners (gs)
  • there is no graded access to the input parameters. You have to go through all of them every single time. A scheme like essential, intermediate, advanced, and expert would allow focus on relevant parameters and you could expand the number of parameters as needed.(gs)

• not easy to figure out what is calculated besides the basics (band structure, DOS, Fermi energy) For example Wien 2K calculates the magnetic moment of a ferromagnetic material but you need to figure out yourself where you can find this number (gs)

The band structure program which will replace Wien 2K as a teaching tool in Ph 575 is named flair and is free. flair is based on the same technology (FLAPW = full-potential linearized augmented plane wave method)) and has pretty much the same strengths in terms of accuracy and speed as Wien 2K. flair exists and is used in research. A few features will hopefully be added before Spring term 2012.

We will use a python based interface (called gem) to interact with flair. The part of gem which handles the setup of a calculation mostly exists and it can read in cif files. The part of gem which handles output exists in parts but needs much more work. Eventually all output of flair will be directly available in python as data structures. gem is the system we use in my research group to do the same calculations you did in class (and some more complicated ones). It is a complex system but it is much easier and more logical than dealing directly with Wien 2K input and output.

On top of gem we will build a web interface unless I hear from you that that is really not needed. A web interface (really a form based interface) will always be limited in its scope (or really expensive) but there is always gem the python layer to access more interesting data.

• all computers in Weniger 412 + 497 (currently >30) can run flair+gem. No more access problems during crunch time.
• It is free and it can run on your Mac and Windows machines too.
• gem has graphics (2D/3D) build in.
• No need to access all parameters of flair. You can concentrate on the important ones.

This is your chance to shape future teaching!

• What features would you like to see?
  • Automatice k-path generation …
  • tool-tips, direct help access.
  • examples?
  • add your ideas …
• Something you tried to do but couldn't?
  • add yours …