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 build on the results obtained from previous years, and continue to work on thermal behavior of homogeneous and heterogeneous clusters. We will mainly focus on new tools that could potentially be very effective in catching solid-like and liquid-like transitions in such clusters, and analyze the transitions as a function of cluster size and/or composition. The systems to be utilized for the analysis include bi-metallic Al/Ni clusters, and during MD runs we will be concentrating on such novelty tools as mixing coefficients and dynamical degrees of freedom, which will be accompanied by a more widely used set of descriptors as caloric curves, RMS bond length fluctuations, heat capacities, power spectra, and DOS. We will pay special attention to the phenomenon of apparent similarity of dynamical degrees of freedom of different clusters subsystems at usually low energies, i.e., the “chameleon effect,” see if this effect is exaggerated by the anharmonicity of the potential, and how it is affected by the size/composition of the cluster (we will analyze the clusters of sizes ~10^2 atoms and up.) For the completion of the work outlined above and the collection of all the necessary descriptors, the average MD run for a single cluster of a specific composition will require, on average, 16 cores/node * 5 nodes * 110 hours of run time = 8,800 core-hours. We estimate that we will study 50 different clusters of various sizes and compositions. Therefore we project that the total computational time will be 8,800 core-hours*50 structures+2000 hours development = 442,000 core-hours. Out of requested 442,000 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: 442000 Q1: 110500 Q2: 110500 Q3: 110500 Q4: 110500 Justification: Storage requirements: Thank You, The LCRC Accounts System