Aditi Datta

Bio: Aditi Datta is an academic researcher from University of Pittsburgh. The author has contributed to research in topics: Stacking fault & Density functional theory. The author has an hindex of 7, co-authored 11 publications receiving 239 citations. Previous affiliations of Aditi Datta include Indian Institute of Technology Kanpur & Indian Institute of Science.

Surface structure and properties of functionalized nanodiamonds: a first-principles study

Abstract: The goal of this work is to gain fundamental understanding of the surface and internal structure of functionalized detonation nanodiamonds (NDs) using quantum mechanics based density functional theory (DFT) calculations. The unique structure of ND assists in the binding of different functional groups to its surface which in turn facilitates binding with drug molecules. The ability to comprehensively model the surface properties, as well as drug‐ND interactions during functionalization, is a challenge and is the problem of our interest. First, the structure of NDs of technologically relevant size (∼5 nm) was optimized using classical mechanics based molecular mechanics simulations. Quantum mechanics based density functional theory (DFT) was then employed to analyse the properties of smaller relevant parts of the optimized cluster further to address the effect of functionalization on the stability of the cluster and reactivity at its surface. It is found that functionalization is preferred over reconstruction at the (100) surface and promotes graphitization in the (111) surface for NDs functionalized with the carbonyl oxygen (C=O) group. It is also seen that the edges of ND are the preferred sites for functionalization with the carboxyl group (‐COOH) vis-` a-vis the corners of ND.

Fast parallel algorithms for short-range molecular dynamics

Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Atomic and Electronic Structure of Solids

Abstract: This text is a modern treatment of the theory of solids. The core of the book deals with the physics of electron and phonon states in crystals and how they determine the structure and properties of the solid. The discussion uses density functional theory as a starting point and covers electronic and optical phenomena, magnetism and superconductivity. There is also an extensive treatment of defects in solids, including point defects, dislocations, surfaces and interfaces. A number of modern topics where the theory of solids applies are also explored, including quasicrystals, amorphous solids, polymers, metal and semiconductor clusters, carbon nanotubes and biological macromolecules. Numerous examples are presented in detail and each chapter is accompanied by problems and suggested further readings. An extensive set of appendices provides all the necessary background for deriving all the results discussed in the main body of the text.