Rp Tyer

Structural and magnetic phase transitions in simple oxides using hybrid functionals

We present the structural as well as elastic properties of the alkaline earth oxides and FeO, calculated using hybrid exchange functionals within DFT. We show that by empirically fitting the amount of Fock-exchange in the hybrid functionals, we can accurately reproduce the pressure-induced phase transitions for MgO, CaO, SrO and BaO. For FeO the hybrid functionals predict an insulator↔metal transition at ca. 150 GPa, associated with an i-B8↔B8 structural phase transition. The structural phase transition is accompanied by a spin transition from a high- to low-spin electron configuration on the Fe2+ ions. Hence, FeO undergoes a magnetic phase transition from an anti-ferromagnetic to non-magnetic structure. We also find that as the ionicity of the polymorphs increases a higher fraction of Fock-exchange is required to reproduce the structural volumes reported from experiments.

Collaborative grid infrastructure for molecular simulations: The eMinerals minigrid as a prototype integrated compute and data grid

This paper describes a prototype grid infrastructure, called the “eMinerals minigrid”, for molecular simulation scientists. which is based on an integration of shared compute and data resources. We describe the key components, namely the use of Condor pools, Linux/Unix clusters with PBS and IBMs LoadLeveller job handling tools, the use of Globus for security handling, the use of Condor-G tools for wrapping globus job submit commands, Condors DAGman tool for handling workflow, the Storage Resource Broker for handling data, and the CCLRC dataportal and associated tools for both archiving data with metadata and making data available to other workers.

Lessons in scientific data interoperability: XML and the eMinerals project.

A collaborative environmental eScience project produces a broad range of data, notable as much for its diversity, in source and format, as its quantity. We find that extensible markup language (XML) and associated technologies are invaluable in managing this deluge of data. We describe FoX, a toolkit for allowing Fortran codes to read and write XML, thus allowing existing scientific tools to be easily re-used in an XML-centric workflow.

Integrating computing, data and collaboration grids: the RMCS tool

We describe RMCS as one of the first tools for grid computing that integrates data and metadata management into a single job submission system. The system is easy to use, with client tools that are easy to install. Although the RMCS system was developed as a prototype, it is now in production use and a number of scientific studies have been completed using it.

eScience for molecular-scale simulations and the eMinerals project

We review the work carried out within the eMinerals project to develop eScience solutions that facilitate a new generation of molecular-scale simulation work. Technological developments include integration of compute and data systems, developing of collaborative frameworks and new researcher-friendly tools for grid job submission, XML data representation, information delivery, metadata harvesting and metadata management. A number of diverse science applications will illustrate how these tools are being used for large parameter-sweep studies, an emerging type of study for which the integration of computing, data and collaboration is essential.

The eMinerals collaboratory: tools and experience

Collaboratories provide an environment where researchers at distant locations work together at tackling important scientific and industrial problems. In this paper we outline the tools and principles used to form the eMinerals collaboratory, and discuss the experience, from within, of working towards establishing the eMinerals project team as a functioning virtual organisation. Much of the emphasis of this paper is on experience with the IT tools. We introduce a new application sharing tool.

Information Delivery in Computational Mineral Science: The eMinerals Data Handling System

Escience technologies are designed to address problems arising in the practice of computational science. The outcome of computational science is the generation of data, and a significant portion of these problems concern Information Delivery: the process of disseminating data across virtual organizations, and of contextualizing that data so that relevant quantities may be extracted and examined with the minimum of difficulty. This paper describes some of these issues encountered in the particular field of computational mineral science, and the solutions that the eMinerals consortium has developed to address them.

Computational Grids for Mid-Sized Collaborative Projects: The eMinerals Experience

Grid computing has the potential to revolutionise how small groups of simulation scientists work together to tackle new science problems. In this paper we report how the eMinerals project has developed a small scale integrated compute and data grid infrastructure - the eMinerals minigrid - and developed generic job submission tools that exploit this infrastructure and which enable the science users to also access other grid systems.

Erratum: The eMinerals collaboratory: tools and experience

M.T. DOVE†, M. CALLEJA, R. BRUIN, J. WAKELIN, M.G. TUCKER, G.J. LEWIS, S. MEHMOOD HASAN, V.N. ALEXANDROV, M. KEEGAN, S. BALLARD, R.P. TYER, I. TODOROV, P.B. WILSON, M. ALFREDSSON, G.D. PRICE, C. CHAPMAN, W. EMMERICH, S.A. WELLS, A. MARMIER, S.C. PARKER and Z. DU Several of the figures in this paper did not reproduce correctly. For higher quality figures, please see the online version of this paper at http://www.tandf.co.uk/journals/ titles/08927022.asp