Hello, A change in allocation has been requested: Requester: bair (Ray Bair) Project: nano-soft-assembly Title: Modeling Self Assembly in Nanostructured Soft Materials Description: Our work targets the molecular and mesoscale regimes, with resolution ranging from 1 nm to several m, where structured morphologies emerge from a balance of entropic forces, enthalpic forces, and interfacial interactions with the environment. Specifically, we will be developing and testing Theoretically Informed Coarse Grained (TICG) simulation strategies for study of emergent structures and dynamics in structured polymers, liquid crystals, and hybrid organic-inorganic composites. This includes advanced-sampling simulation algorithms for atomistic or particle-based TICG simulations of nanostructured self-assembling materials and complex fluids. The algorithms and code will take advantage of parallel computing capabilities at both LCRC and ALCF. The proposed theoretical and computational formalism will be capable of describing dynamic processes. It will offer a number of attractive features, including the ability to describe large, fully three-dimensional realizations of the materials of interest and their dynamics while incorporating entanglements, hydrodynamic effects, and thermal fluctuations, and it will serve as a screening and design tool that will allow users to focus on promising materials combinations, and to interpret large amounts of high throughput data efficiently. Current: undetermined amount Justification: Requested: 180000 A specific reason has been given: Requested: March +25,000, April-Sept +160,000 Fusion is ideally suited to performing mid-sized parallel simulations; here we explain recent work we have done which has benefited from use of the Fusion cluster. To date, my investigations with fusion have involved two sets of investigations for coarse-grained molecular dynamic models: large classical molecular dynamics simulations, and parallel enhanced sampling techniques. I have utilized parallel molecular dynamics to investigate a model of smectic liquid crystalline elastomers, demonstrating the first model able to capture the polydomain–monodomain transition at molecular scale. To do this, long simulation times of N = 80,000 cross-linked Gay–Berne particles were needed, necessitating parallelization across multiple nodes. Further, I have investigated the interactions of nanocolloidal particles solvated in liquid crystals, or at the surface of liquid-crystalline droplets, with an eye toward self-assembly applications. It is known that small nanoparticles or impurities such as lipids, will segregate to liquid crystalline defects, with an affinity depending on their size and anchoring (surface–LC) interactions. I aim to establ ish rigorously the origin of these forces, and the magnitude one might expect for particulate inclusions of varying anchoring potential. This is facilitated greatly through enhanced sampling techniques such as multiple-walker metadynamics and umbrella sampling. These techniques benefit from the ability to run multiple simultaneous copies, communicating information about system configurations or applied energetic bias. Each system in this case takes up a single node, with 8–25 communicating simulations on the cluster. Two manuscripts have come out of this work, with two more in preparation. The work in progress relies on the continuing presence of resources such as Fusion to enable parallel enhanced-sampling calculations. I am in the process of calculating nanoparticle potentials of mean force within LC droplets, where the long relaxation times and deep energy wells necessitate these techniques. With continued presence on Fusion, I intend also to perform calculations of surfactant driven phase transition dynamics within LC droplets. Additionally, I am involved in work to develop an exciting new method for polymers in electrohydrodynamic flows that will benefit from access to the fast processors on the Fusion cluster. • “Modeling the polydomain-monodomain transition of liquid crystal elastomers,” J. K. Whitmer, Raj Shekhar, T. F. Roberts, N. L. Abbott and J. J. de Pablo. Physical Review E 87, 020502(R) (2013). • “Liquid-Crystal Mediated Nanoparticle Interactions and Gel Formation,” J. K. Whit- mer, A. A. Joshi, T. F. Roberts and J. J. de Pablo. Journal of Chemical Physics, submitted (2013). • “Particle–Defect interactions in Liquid-Crystal Nanodroplets,” J. K. Whitmer, J. C. Armas-Perez, A. A. Joshi, T. F. Roberts and J. J. de Pablo. in preparation (2013). • “Nanoparticle solvation in liquid crystal phases,” J. K. Whitmer, J. C. Armas-Perez, A. A. Joshi, T. F. Roberts and J. J. de Pablo. in preparation (2013). This needs to be approved and the final allocation amount decided upon. Thank You, The LCRC Accounts System