Visual ASE (V.A.S.E.)

I have recently been developing a graphical interface to the CAMP simulation codes Dacapo and Asap, using their common interface ASE (Atomic Simulation Environment)

The interface is written in Python and uses Tkinter (the Python interface to Tcl/Tk) for the graphical features (Dialog boxes, menus etc.). In its first incarnation it was specifically designed with exercises to do with carbon bonding and carbon nanotubes in mind, and was called Cbond. It was used in this way for the first module of first-year DTU course Physics and Nanotechnology. It is now under development to handle a new set of simulations (featuring small metal clusters) to be used in the last module of P & N, as well as the first year introduction to thermodynamics course, both of which will take place in Spring 2005.

Basic use

The program is started by typing "VASE [structure module]" where (so far) the structure module can be "Carbon" or "Cluster". The choice determines what structures are available to choose from the "Structures" menu after start-up. Typing the old name "Cbond" is equivalent to VASE Carbon. If no structure module is specified, for now Cluster is chosen by default, after a warning message is printed, but this may be temporary.

A screen shot of the main window appears below. The most important buttons are at the top. The user must choose a structure and a computation, each of which leads to further choices of parameters. Then pressing "RUN" starts the computation (which may be simply the calculation of the energy of the given structure, or a series of energies as the structure is deformed in some way, or running molecular dynamics on the structure). The structure options always include reading from a file and using the output of the last calculation. The "MetaComputation" button allows one to concatenate several computations, changing a parameter between each one.

The results of cmputations are printed to the terminal window if only a few numbers are involved, or written to a file (whose name was a parameter to be specified by the user). The final state of the structure can also be visualized using the "Visualize" button.

Availability

The code is available from CAMP's CVS repository. If you do not have access to this you may contact me for it. You will have to install ASE, Asap and Dacapo separately, however. Please see the appropriate web pages for instructions on how to do that.

As of this writing (2/12/2004) the code is in quite a state of flux, as I have been adding new features which have required major restructuring, as well as trying to simplify it by further restructuring.

Exercises using VisualASE (formerly known as Cbond)

Here is a postscript file of the problem set used by the first year students for the computation section of the nanotubes module. It is more work than there was time for (2 x 2 hours in the lab plus up to 4 hours of their own time), so some sections were not required (apart from those marked "optional").

Here is postscript file of an exercise worksheet prepared for use by visiting high school teachers. These only had 90 minutes so it is much shorter than the students' problem set. No analysis of data was included, it was mostly visualization and some simple simulations with nanotubes.


V.A.S.E. Screen shots

Main window

Choosing a structure

Choosing parameters for the structure

Choosing an element

Choosing a computation

A (7,3) carbon nanotube

A spherical cluster of Cu atoms

Lowest energy wavefunction from a dacapo calculation of bulk diamond


This page was last modified on 2/12/04

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