Modeling Nano-Materials Intelligently

a medium scale focused project under joint Indo - EU commission on scientific collaboration

FP7-NMP-2008-EU-India-2

Modeling Nano-Materials Intelligently

a medium scale focused project under joint Indo - EU commission on scientific collaboration

FP7-NMP-2008-EU-India-2

The modeling of nano materials and nano structures is challenging on many counts. Firstly, traditional approximations like the separation of length and time scales become questionable in this regime, necessitating a multi scale approach. Secondly, there is often an interplay of quantum and classical effects making a dialog between experts in these two communities necessary. Lastly, one needs to dedicate considerable amount of numerical or computational resources in terms of both equipment and simulational tools in order to obtain realistic results. Therefore, in the present research proposal we aim to develop methods based on multiscale synthesis and a computational or simulational approach to understand, design and create novel nanostructures with useful functional and material properties. An unique feature of the present proposal is to use both quantum as well as classical simulation tools to understand the physics of nanomaterials at varying length scales. The project will involve improving and augmenting the existing methods as well as design new techniques which aim to bridge length scales. The breadth of applications range from novel magnetism, quantum transport, NMR in nanosystems to confinement in nano pores and self-assembly of nano-particles. The work to be carried out in the project will lead not only to significant understanding of the physics of nanomaterials but also to the development of software tools and packages for future use.

Materials modeling and simulation classified in terms of length and time scales is a convenient way of approaching the subject of this proposal. One can recognize that there are four natural approaches which are used in successive manner for the simulations/modeling of materials properties at different length/time scales:

Electronic scale: Here the material is explicitly represented by nuclei and electrons. Quantum mechanical methods are used to describe the behavior of the electrons which determine the properties and structures of the material.

Atomistic scale: Here the electronic degrees of freedom are ignored, and molecular mechanical models and classical mechanics are applied to describe the behavior of atoms and molecules. The most common technique here is MD simulations, now routinely carried out on systems including up to tens of thousands of particles over tens of nano seconds.

Mesoscopic scale: It can be considered as a supra-atomic scale where uninteresting or fast details of the atomic motions are averaged out or replaced by stochastic terms, thus concentrating on essential motions and large-scale structures. This leads to the so-called coarse-grained models in which the fundamental unit is a set of beads that interact with other beads via effective soft potentials.

Macroscopic scale: At this level material is assumed to be continuously distributed throughout its volume by disregarding the discrete particle-based structures. This is the materials we see, touch and manufacture. To enter the macroscopic scale from the meso-scale represents a big challenge in contemporary modelling. One way is to create hierarchical mesh structures; other ways are to use thermodynamical or kinetic modelling.

Our plan is to transcend the scales though hierarchical modeling through the electronic, atomistic, mesoscopic and macroscopic blocks. The MONAMI work plan is organised into four work packages (WP) each having several tasks. The first three work packages are devoted to a comprehensive understanding of various properties of nano materials by using computer modelling and simulation tools as applicable in different length scales. WP-1 is devoted to understand the properties of nano systems using ab-inito electronic structure calculations. WP-2 is employed to understand properties of nanomaterials where classical (atomistic) simulation is adequate. WP-3 will deal with density based multiscale modelling for the properties of nanostructured materials. WP-4 is devoted to parallel algorithms and a common language between existing software necessary to understand properties of nano materials.

Objectives