[ase-users] [gpaw-developers] ASE tutorial slides needed

[Jens Jørgen Mortensen]

On Wed, 2010-10-27 at 08:59 -0600, Nichols A. Romero wrote:
> Hi,
> 
> We are doing an ASE & GPAW tutorial here at ANL. I have gotten some nice GPAW slides
> from a few of you (JJ, Jussi). Many thanks.
> 
> Does anyone have any tutorial slides for ASE? Preferably basic usage, e.g. how to
> construct cells, different calculators, etc. It would be useful to have the
> source files (LaTeX, OpenOffice, PowerPoint, whatever).

It's always fun to demonstrate ASE in an interactive Python session.
Last time I did that, I did this in the interpreter:

from ase import Atoms
h2 = Atoms('H2',
           [(0, 0, 0),
            (0, 0, 0.7)])
from ase.calculators.emt import EMT
h2.set_calculator(EMT())
print h2.get_forces()
from gpaw import GPAW
h2.set_calculator(GPAW())
h2.cell
h2.center(vacuum=2.5)
h2.cell
from ase.visualize import view
view(h2)
from ase.all import *
f = h2.get_forces()

Here are some reStructuredText slides:

The atomic simulation environment (ASE) Python package
------------------------------------------------------

* We use ASE for structure optimization, molecular dynamics, handling
  constraints, nudged elastic band calculations, vibrational analysis,
  simulated STM images, calculation of Wannier functions, transport
  calculations and much more

* Calculators with ASE interface:

  .. image:: images/ase.png
     :width: 5cm
     :align: center

* ASE also has a graphical user interface and a rich set of file-IO
formats

* http://wiki.fysik.dtu.dk/ase



ASE-calculator interface
------------------------

For ASE, a calculator is a black box that can calculate energies,
forces and stresses.  From ASE it will get:

* atomic positions
* atomic numbers
* the unit cell
* boundary conditions

and maybe also magnetic moments and charges.

More advanced interface:

* Eigenvalues.
* Electron densities.
* Wave functions.
* ...


Different types of calculators
------------------------------

* 1) ASE writes input file
  2) ASE starts Fortran code (maybe in parallel)
  3) ASE waits for Fortran code to finish
  4) ASE reads output file

* Same as above, except that the Fortran code doesn't stop - it waits
  for a new input file with new coordinates.

* Pure Python solution.  For parallel calculations, the Python
  interpreter runs on all processes.

Jens Jørgen