Efficient Parallel Generation of Many-Nucleon Basis for Large-Scale Ab Initio Nuclear Structure Calculations

The International Journal of High Performance Computing Applica

2023

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High performance computing (HPC) applications that work with redundant sequences of data can benefit from their deduplication. We study this problem on the symmetry-adapted no-core shell model (SA-NCSM), where redundant sequences of different kinds naturally emerge in the data of the basis of the Hilbert space physically relevant to a modeled nucleus. For a fast solution of this problem on multicore architectures, we propose and present three multithreaded algorithms, which employ either concurrent hash tables or parallel sorting methods. Furthermore, we present evaluation and comparison of these algorithms based on experiments performed with real-world SA-NCSM calculations. The results indicate that the fastest option is to use a concurrent hash table, provided that it supports sequences of data as a type of table keys. If such a hash table is not available, the algorithm based on parallel sorting is a viable alternative.

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Section: Applicationmentioning

confidence: 99%

Parallel multithreaded deduplication of data sequences in nuclear structure calculations

The International Journal of High Performance Computing Applica

2023

Self Cite

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“…This article is an extended version of our conference paper (Langr et al, 2018), where we introduced the accelerated basis generation algorithm and presented its performance measurements carried out using mostly our test-bed system. Here, we additionally: describe the SU ( 3 ) -scheme many-nucleon basis and associated symmetry-based selection rules that specify an SA-NCSM model space (Section 3); provide a description of many-nucleon basis construction utilized by the SA-NCSM framework (Section 3); present both the baseline and the accelerated basis construction algorithms in agreement with notation and terminology introduced by Section 3; and report and discuss more thorough experimental results obtained on one of the most powerful supercomputers in the world. …”

Section: Introductionmentioning

confidence: 99%

“… 3. J is a standard symbol for denoting the total angular momentum. However, to maintain consistency with our conference paper (Langr et al, 2018), we use J in this article also for denoting a process column coordinate. These two meanings should be clearly distinguishable from the context at each particular place. …”

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confidence: 99%

Accelerating many-nucleon basis generation for high performance computing enabled ab initio nuclear structure studies

The International Journal of High Performance Computing Applica

Launey

et al. 2019

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We present the problem of generating a many-nucleon basis in SUð3Þ-scheme for ab initio nuclear structure calculations in a symmetry-adapted no-core shell model framework. We first discuss and analyze the basis construction algorithm whose baseline implementation quickly becomes a significant bottleneck for large model spaces and heavier nuclei. The outcomes of this analysis are utilized to propose a new scalable version of the algorithm. Its performance is consequently studied empirically using the Blue Waters supercomputer. The measurements show significant acceleration achieved with over two orders of magnitude speedups realized for larger model spaces.

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Parallel Identification of Unique Sequences in Nuclear Structure Calculations

Lecture Notes in Computer Science

2023