Development of wide-ranging functionality in ONETEP

Lead Research Organisation: University of Cambridge
Department Name: Physics

Abstract

Quantum mechanics has had a profound and pervasive influence on science and technology. Phenomena that are intrinsically quantum mechanical, such as magnetism, electron transport in semiconductors, and the effect of impurity atoms in materials, lie at the heart of almost every branch of industry. Quantum mechanical calculations of properties and processes from ``first-principles'' are capable of making accurate quantitative predictions but require solving the Schrdinger equation which is extremely difficult and can only be done using powerful computers. In contrast, empirical modelling approaches are relatively cheap but lack the predictive power of first-principles methods (which are parameter-free and take as input only the atomic numbers of the constituent atoms). The predictive capability is essential, in order to make rapid progress on new and challenging problems where there is insufficient experimental data and to also generate useful empirical approaches or even to check their reliability when these exist. Within the class of first-principles methods, one approach that has been outstandingly successful is the Density Functional Theory (DFT) as it combines high accuracy with moderate computational cost. Nevertheless, the computational effort of performing calculations with conventional DFT approaches increases as the cube of the number of atoms, making them unable to tackle problems with more than a few hundred atoms even on modern supercomputers. Since the pioneering work of the Nobel laureate Walter Kohn, it has been known that it is possible to reformulate DFT so that it scales linearly, which would in principle allow calculations with many thousands or even millions of atoms. The practical realisation of this however, in a method which is as robust and accurate as conventional cubic-scaling DFT approaches has been extremely difficult. The ONETEP approach developed over many years by the applicants of this proposal has achieved just that. ONETEP is at the cutting edge of developments in first principles calculations. However, while the fundamental difficulties of performing accurate first-principles calculations with linear-scaling cost have been solved, only a small core of functionality is currently available in ONETEP which prevents its wide application. In this collaborative project between three Universities, the original developers of ONETEP will lead an ambitious workplan whereby the functionality of the code will be rapidly and significantly enriched. The code development ethic of ONETEP, namely that software is robust, user-friendly, modular, portable and highly efficient on current and future HPC technologies will be of fundamental importance and will be further strengthened by rigorous cross-checking between the three institutions of this proposal. The developments are also challenging from a theoretical point of view as they need to be within the linear-scaling framework of ONETEP, using its highly non-trivial formulation of DFT in terms of in situ optimised localised functions. The program of work provides much added value as the few fundamental enabling technologies that will be developed in its first stages will then underpin many of the functional capabilities that will follow. The result will be a tool capable of a whole new level of materials simulation at the nanoscale with unprecedented accuracy. It will find immediate application in simulations in molecular biology, nanostructures and materials, which underpin solutions in urgent current problems such as energy, environment and health. Through the increasing number of commercial and academic users and developers of ONETEP, the worldwide dissemination and wide use of this novel tool will be rapid; finally the expanding ONETEP Developers' Group will coordinate the best strategies for the future maintenance and development of the software.
 
Description This project has increased the speed and functionality of the linear scaling density functional theory code ONETEP which allows quantum mechanical calculations to be applied to systems containing many thousands of atoms.
Exploitation Route ONETEP is used in industry already but I expect that exemplar calculations presently being carried out demonstrating both the enhanced functionality and the increase in speed will lead to in increased volume of commericial sales of the code. The ONETEP code is available to industry and academics - it is licenced to Acclelrys.
Sectors Chemicals,Electronics,Energy,Healthcare,Pharmaceuticals and Medical Biotechnology

URL http://www2.tcm.phy.cam.ac.uk/onetep/
 
Description This grant allowed the addition of a range of functionality to the ONETEP code and, equally importantly, software and algorithm development to considerably speed up the code. The aim of this work was to allow a wider range of science to become accessible to first principles density functional theory simulations. Given that the ONETEP existed before this grant, the work had an impact from the very beginning of the funding period. However, a key challenge to this approach is that, by definition, large systems are associated with long timescales and while ONETEP addresses the system size challenge the timescale problem remains a challenge though now (ie 2014) increased computational resources and new techniques for phase space searching are beginning to address this final issue. This, in time, will allow ONETEP to be used as routinely and widely as 'conventional' codes are at present. ONETEP was sold commercially during the whole of this grant period.
First Year Of Impact 2009
Sector Chemicals,Electronics,Energy
Impact Types Economic

 
Description E-Infrastructure Leadership Council
Geographic Reach National 
Policy Influence Type Participation in advisory committee
Impact I believe that I have done much to make Government and Research Funders recognise that development of high quality software is an intellectual pursuit of itself (rather than only the application of this software to a scientific problem)..
URL https://www.gov.uk/government/groups/e-infrastructure-leadership-council
 
Description Biovia (formerly Accelrys) 
Organisation Dassault Group
Department BIOVIA
Country United States 
Sector Private 
PI Contribution We develop ONETEP, Biovia sell it.
Collaborator Contribution The ONETEP Developers Group created and continue to develop the code.
Impact http://www2.tcm.phy.cam.ac.uk/onetep/Main/Publications
 
Title ONETEP 
Description ONETEP is a linear scaling quantum mechanical atomistic simulation tool 
Type Of Technology Software 
Impact This software is continuously improved in terms of both functionality and speed. It has been sold commercially by Biovia (formerly Accelrys) since 2004 and now has commercial sales in excess of $4.5million 
URL http://accelrys.com/products/materials-studio/quantum-and-catalysis-software.html