The CCP1 GUIPaul Sherwood, Huub van Dam and Jens ThomasWithin the commercial software sector, a number of powerful GUIs exist, but these are tied to particular programs and are not designed to facilitate interoperability. In fact, in the commercial sector the quality of the interface is often the differentiator between different software providers. In contrast the academic community, as exemplified by CCP1, has a focus on scientific software and GUI development has been a low priority. In our case, the use of an open source model ensures that distribution with any other software (for profit or otherwise) is possible and thereby encourages participation by the whole community. The current software has the status of a usable prototype which is written in Python. The visualisation is provided by the open source VTK library and a number of other Python modules, such as Tkinter. Once these tools are installed the GUI should run in any modern environment. Our GUI development has the following characteristics:
FunctionalityThe program contains a simple molecule builder which allows construction of molecules using internal (z-matrix) coordinates as well as customary point-and-click editing. This tools is quite well suited for embedded cluster (QM/MM) calculations as it is possible to build up a reacting centre in z-matrix coordinates from an active site in a matrix defined in cartesian coordinates (Figure 1).
Figure 1 Constructing a model for a reaction at a zeolite acid site using the Z-matrix builder. It is then possible to open input editors which assist in the preparation of input datasets for a number of codes, at present primarily GAMESS-UK. An interface to QM/MM modelling within the ChemShell package is also being developed, which will allow the preparation of clusters for the modelling of periodic materials.
Figure 2. The GAMESS-UK Calculation editor is based on a notebook widget A variety of standard post-analysis options are available, including optimised geometries, animation of vibrational frequencies, plotting of densities, orbitals and electrostatic potentials. One of the most popular ways to represent the electrostatic potential is to display it as a colour map on an isodensity surface (Figure 3).
Figure 3 Visualisation of electrostatic potential on an isodensity surface Advanced Visualisation CapabilitiesThe use of VTK opens up a range of advanced visualisation techniques. One area we have started to explore is that of vector visualisation, a tool which can be used to represent the electric field and also, for those using Baders AIM approach, topological features of the charge density. Volume visualisation, which will probably be most familiar from CAT and ultrasound scan images, is also supported (see Figure 4).
(a) (b) Figure 4 (a) Visualising the electric field around the TNT molecule. (b) vector and volume visuation, electric field and potential around water. Grid FunctionalityRemote job submission onto HPCx has been demonstrated using ssh (PPK authentication) in preparation for grid enabling, and we have also started work on using Condor pools. We anticipate adding Globus support next year. OutlookWe plan to ship the GUI with the next release of GAMESS-UK, early in the New Year. The GUI has recently featured in GAMESS-UK training events and in the most recent of these (Linkoping, October 2004) we initiated collaboration with the Dalton developer community in which they will adapt the GUI to support Dalton. This will advance the principal goal of the project, i.e. to provide support for a range of academic quantum chemistry packages and will simplify the interfacing of new codes, e.g. MOLPRO which are planned for the coming year. Further InformationSee the GUI web page for more information and download instructions.
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