Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Darya Aleinikava Project Name: Anharmonic_systems Division: CSE Project title: Analysis of dynamical complexities of highly anharmonic systems Associated funding: Other Systems: High-performance GPU cluster Golem Science: The goal of this project is to continue the study of the dynamical complexities of systems with arbitrary degree of anharmonicity. The first objective of this work is to calculate the exact density of states (DOS) of finite-size systems, such as atomic clusters, and to use it to analyze their properties as a function of composition and size. DOS is the central figure of statistical mechanics since it is the basis for computation of all the other statistical mechanical characteristics, and it also plays a major role in theories of chemical kinetics because it allows a direct evaluation of reaction rate constants. The non-trivial problem of finding DOS for arbitrarily anharmonic systems has been researched extensively over the last 60 years, but no exact solution that would be applicable in all cases was found. We developed the exact solution in the frameworks of both classical and quantum mechanics and implemented it in the form of efficient algorithms. The solution involves MD simulations and analysis of data generated dynamically. Specifically, will produce power spectra, which serve as an input into t he newly developed algorithms, yielding the exact anharmonic density of states thus eliminating the need to use various approximations. As the second aspect of the project we will address the problem of mixing in heterogeneous systems, where we plan to utilize such descriptors as mixing coefficient and dynamical degree of freedom, collected during MD simulation runs, to investigate the structural changes of different isomers during high-energy dynamics which is of particular importance in the study of multiple-steps melting transitions. Project description: We are planning to focus on the analysis and characterization of the thermal behavior of homogeneous and heterogeneous (specifically, pure Al and Ni, and bimetallic Al/Ni) clusters as a function of size and composition, including the phenomenon of their solid-like to liquid-like transition. During MD simulations we will collect data for various descriptors, which include caloric curve, root-mean-square bond length fluctuation, heat capacity, mixing coefficient, dynamical degree of freedom, power spectrum, and DOS. These will be obtained and analyzed for the entire clusters as well as their subsystems. The work will cover a broad range of sizes (up to ~10^2 atoms) and compositions. In order to obtain the necessary data for the characterization of DOS as a function of energy, together with the other mentioned descriptors, the typical (on average) MD runs will require 16 cores/node * 5 nodes * 100 hours of run time = 8000 core-hours. The calculation of energy dependence of density of states for each cluster will amount to 16 cores/node*5 nodes*0.1 hours=8 core-hours. Thus to analyze one cluster of specific composition, 8000 core-hours + 8 core-hours=8008 core-hours will be required. The total computational time for 85 different sizes and compositions (the estimated scope of the planned computations) will be 8008 core-hours*85 structures+1000 hours development = 681,680 core-hours. Out of requested 681,680 core-hours, 2% of the time will be allocated for single-core jobs. The number of people to run these simulations is 2. Industry partnership: Project URL: Current FY Hours Used: undetermined amount New FY Requested allocation: 681680 Q1: 170420 Q2: 170420 Q3: 170420 Q4: 170420 Justification: In the upcoming year we are planning to increase the scope of the systems considered. Last year the requested allocation was 452,500 core-hours. Based on the length of runs submitted, and taking into account the planned increase of the systems' size, we project that this year 681,680 core-hours will be needed, and that we will be able to use them efficiently. Storage requirements: Thank You, The LCRC Accounts System