Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Peter Zapol Project Name: glassforms Division: MSD Project title: First-principles Calculations of Mineral and Glass Dissolution Associated funding: DOE-NE Other Systems: Science: The dissolution of glass forms in nuclear waste disposal determines their long term stability, which is critical for evaluating disposal scenarios. The dissolution behavior of minerals and glasses has been found to strongly depend on the pH value of the aqueous environment. The delicate balance of ions at the solid-water interface in aqueous solutions is still a big challenge both for accurate computational modeling and for unambiguous experimental measurements. This project aims to develop physical models to simulate the water-borosilicate glass forms interface at the atomic level under various pH conditions and to calculate the rates of dissolution for Si, Al and other constituting elements under acidic, neutral and basic conditions. These studies are based on first-principles calculations and kinetic Monte Carlo simulations. The calculated reaction barriers by using DFT calculations can then be used as input in kinetic Monte Carlo simulations to estimate the over all dissolution rates and compare with experimental values. These investigations will be very important to better understanding of the dissolution behavior and prediction of dissolution rates. Project description: The first-principles calculations will be carried out using the electronic-structure code VASP. NEB calculations will be performed to calculate the reaction pathways for a variety of composing elements under acidic, neutral and basic conditions. A single optimization calculation takes 48 hours on 32 processors. Last year, we have performed calculations on glass with B, Si and Na and made structures with Al and started hydrolysis reaction calculations with Al-containing glass. This year, we will continue with calculations of reaction barriers. We are considering 60 supercell samplings of silicate glasses including multiple components (Si, Al, B, Na, K). The calculation for possible reactants, intermediates, products will take about 200,000 core hours. It takes about 50 hours on 160 processors (5 images) to calculate a reaction barrier along the reaction pathway. The total estimated computer time for barrier calculation is 640,000 core hours. kMC simula tion will be performed to simulate the dissolution process of glass for 4 different temperatures and 4 different pH values for 72 hours (each simulation should run 50 times in order to get the statistical results). That requires 70,000 core hours. In sum, the total requested allocation for this project is 910,000 core hours. Industry partnership: Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 910 Q1: 230 Q2: 230 Q3: 220 Q4: 230 Justification: This project will primarily use the density functional theory (DFT) implemented in electronic structure code VASP. The system sizes of our calculations ranges from 100 to 300 atoms. VASP has been tested to scale very well in parallel processing on Blues. The optimum number of processors used for these systems is 16-64 processors per calculation. The kMC simulation code is written in Fortran. Storage requirements: Thank You, The LCRC Accounts System