It is a small request, so lets approve it. Ray On 12/2/15, 8:21 AM, "Phillips, Carolyn L." <[email protected]> wrote:

I would like to request an additional 25,000 hours for Q1 and that my allocation for Q2 be increased to 50,000 hours.

Begin forwarded message:

From: <[email protected]<mailto:[email protected]>> Subject: [LCRC Accounts] Project Renewal Request: Metadynamics_LC Date: October 1, 2015 at 1:44:41 PM CDT To: <[email protected]<mailto:[email protected]>> Reply-To: <[email protected]<mailto:[email protected]>>

Carolyn Phillips,

Thank you for submitting a renewal request for your LCRC Project for the coming fiscal year. The LCRC Allocations Committee will consider your request at its September meeting. You will be notified by email when a decision is made for your project's renewal. A copy of your request is included below for your records and has been sent to all PIs of this project:

Submitter/PI: Carolyn Phillips Division: MCS Project Name: Metadynamics_LC Project Title: Using Parameter Free Metadynamics to calculate LC elastic constants Associated Funding: Internal ANL LDRD 2015-172-N0 Other Systems: Science: We will be exploring and expanding the state-of-the-art metadynamics methods in the context of measuring the mechanical properties of materials, and specifically initially, the elastic properties of liquid crystals Project Description: We will be using a parameter-free metadynamics method for an atomistic model of a liquid crystal 4-n-pentyl-4¹-cyanobiphenyl (5CB), as well as the homologous series (6CB,7CB,8CB).

Each nCB molecule will be simulated via a coarse-grained united-atom approximation in a classical N-body Molecular Dynamics code. We will be using NAMD + PLUMED2. Simulations will be used to measure the elastic constants of each liquid crystal system using metadynamics.

NAMD is a well-parallelized stable MD code with a history of use by other users on Blues. Equilibrium simulations of the correct scale of the model described above parallelized across on 4x16-core nodes required ~300 MB of memory and ~36 hours to implement 10 million time steps. However most simulations will also be paired with PLUMED2, a parallelized version of PLUMED1.3 that can be used to implement metadynamics. Metadynamics is not known to perform well in parallel, due to a relatively high frequency of communication across all nodes, so I do not expect to use more than 1-4 nodes for individual "walkers" (simulation implementations). Instead production run simulations will likely use multiple (~20) "walkers" each deployed on 1-4 nodes, thus requiring ~80 nodes at a time. We will be evaluating trade-offs in length of simulation, number of nodes per implementation, and number of walkers to achieve convergence. Thus a better approximation of the allocation required to

complete this project will result from the initial scoping stage of this project.

Previous MD + metadynamics simulations have been performed on a different model of the system using a different MD code on Midway at UChicago. Small runs using NAMD on Blues and Fusion have already been issued to gain familiarity.

Expected number of Project Members: 2 Industry Partnership: Project URL: New FY Requested Allocation: 150000 for Q1: 25000 for Q2: 25000 for Q3: 50000 for Q4: 50000 Efficiency: Storage Requirements:

If you need to amend this project renewal, please contact LCRC Support at [email protected]<mailto:[email protected]>.

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