Carlo Manuali

COMPCHEM: Progress Towards GEMS a Grid Empowered Molecular Simulator and Beyond

Foundations and structure of the building blocks of GEMS, the ab initio molecular simulator designed for implementation on the EGEE computing Grid, are analyzed. The impact of the computational characteristics of the codes composing its blocks (the calculation of the ab initio potential energy values, the integration of the dynamics equations of the nuclear motion, and the statistical averaging of microscopic information to evaluate the relevant observable properties) on their Grid implementation when using rigorous ab initio quantum methods are discussed. The requests prompted by this approach for new computational developments are also examined by considering the present implementation of the simulator that is specialized in atom diatom reactive exchange processes.

GriF: A Grid framework for a Web Service approach to reactive scattering

Abstract Grid empowered calculations are becoming an important advanced tool indispensable for scientific advances. The possibility of simplifying and harmonizing the work carried out by computational scientists using a Web Service approach is considered here. To this end, a new Collaborative Grid Framework has been developed and tested. As a study case a three dimensional reactive scattering code dealing with atom–diatom systems has been considered. To this end an extended study of the energy dependence of the electronically adiabatic reactivity of N + N 2 has been performed on the EGEE Grid.

GriF: A new collaborative framework for a web service approach to grid empowered calculations

A new Collaborative Grid Framework named GriF has been developed and validated to run on the Grid by considering as a study case quantum reactive scattering codes. Its use as a tool of Science Gateways to facilitate massive calculations also with the aim of improving scientific collaboration is discussed. Accordingly, a preliminary study on how to profile the users of virtual organizations in order to pave the way to a systematic evaluation of the work carried out in the Grid and to foster its sustainability, is presented.

A grid credit system empowering virtual research communities sustainability

In this paper a new Grid Credit System called GCreS specifically designed for evaluating Grid Virtual Organizations and Virtual Research Communities is presented. GCreS is based on the Evaluation of the Quality of Services and Users of the considered Community. To this end, use is made of a SOA Framework called GriF and of its features useful to support the analysis of Grid activities. Its first application to the Virtual Organization COMPCHEM is also discussed.

Linear algebra computation benchmarks on a model grid platform

The interest of the scientific community in Beowulf clusters and Grid computing infrastructures is continuously increasing. The present work reports on a customization of Globus Software Toolkit 2 for a Grid infrastructure based on Beowulf clusters, aimed at analyzing and optimizing its performance. We illustrate the platform topology and the strategy we adopted to implement the various levels of process communication based on Globus and MPI. Communication benchmarks and computational tests based on parallel linear algebra routines widely used in computational chemistry applications have been carried out on a model Grid infrastructure composed of three 3 Beowulf clusters connected through an ATM WAN (16 Mbps).

Efficient workload distribution bridging HTC and HPC in scientific computing

GriF is a Workflow Management System designed to support users of the Molecular and Materials Sciences and Technologies COMPCHEM Virtual Organization. In particular, GriF manages the results of the parameter sweeping studies submitted to the Grid. This service has been recently extended to implement seamless access to both High Performance and High Throughput Computing architectures. To this end, the Workflow execution is splitted into single blocks whose execution is most suited to one or the other platform. This has been obtained by implementing a communication channel allowing interoperability between the gLite middleware operating on the Italian Grid Initiative segment accessible to COMPCHEM and the software stack operating on the CINECA machines. As a prototype application a high level ab initio calculation of the potential energy surface of few atom system has been implemented.

Grid Computing in Computational Chemistry

The adoption of grid computing (GC) in computational chemistry and the assemblage for that purpose of specific virtual organizations and a virtual research community are discussed. The discussion focuses in particular on the development of a new synergistic GC model best suited for computational research and applications in the field of chemistry and molecular and materials sciences and technologies. The program and the tools designed and/or utilized for achieving such goal as well as the objectives achieved in this endeavor are also discussed.

A Trial User, Resources and Services Quality Evaluation for Grid Communities Sustainability

We discuss here the possibility of utilizing the innovative features of GriF (a Grid Framework allowing the guided management, monitoring and results recollection of computational simulations under the form of advanced Grid Services) to the end of empowering the Chemistry, Molecular and Materials Sciences and Technologies communities with a set of quality evaluation functions. For this purpose, the enhanced options offered by GriF in terms of Quality Evaluation have been tested on the trial Virtual Research Environment of the COMPCHEM Virtual Organization for ranking resources, users and services. The results obtained are analysed with the purpose of addressing the Sustainability problems of Virtual Research Communities.