Computer Physics Communications最新文献

{"title":"Implementation and optimisation of the cdugksFoam solver on the Sunway TaihuLight supercomputer","authors":"Jie Guo ,&nbsp;Yunlan Wang ,&nbsp;Rui Zhang ,&nbsp;Feifei Zhang ,&nbsp;Tianhai Zhao ,&nbsp;Congshan Zhuo ,&nbsp;Sha Liu ,&nbsp;Chengwen Zhong","doi":"10.1016/j.cpc.2024.109455","DOIUrl":"10.1016/j.cpc.2024.109455","url":null,"abstract":"<div><div>In this study, the cdugksFoam solver was successfully implemented on the Sunway TaihuLight system using the MPI + Athread programming model. To utilise the heterogeneous SW26010 many-core processor fully, we implemented three levels of parallelisation: MPI process-level hybrid parallelisation in physical space and velocity space, thread-level parallelisation to further partition physical space, and single-instruction multiple-data (SIMD) vectorisation. To address the performance bottleneck caused by the low memory bandwidth of the SW26010 processor, a series of optimisation methods, including kernel fusion, transcendental function optimisation, and soft cache, were designed and implemented to reduce discrete memory access and improve the computational efficiency of CPEs. The accuracy of the optimised program was validated through simulations of the 3D lid-driven cavity flow and rarefied supersonic flow past a sphere. Based on the experimental results from multiple grid scales, the overall performance achieved an acceleration of over 5 times compared to running on the management processing elements. In both strong and weak scalability tests, a parallel efficiency exceeding 90% was achieved.</div></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":"308 ","pages":"Article 109455"},"PeriodicalIF":7.2,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectral scheme for atomic structure calculations in density functional theory","authors":"Sayan Bhowmik ,&nbsp;John E. Pask ,&nbsp;Andrew J. Medford ,&nbsp;Phanish Suryanarayana","doi":"10.1016/j.cpc.2024.109448","DOIUrl":"10.1016/j.cpc.2024.109448","url":null,"abstract":"<div><div>We present a spectral scheme for atomic structure calculations in pseudopotential Kohn-Sham density functional theory. In particular, after applying an exponential transformation of the radial coordinates, we employ global polynomial interpolation on a Chebyshev grid, with derivative operators approximated using the Chebyshev differentiation matrix, and integrations using Clenshaw-Curtis quadrature. We demonstrate the accuracy and efficiency of the scheme through spin-polarized and unpolarized calculations for representative atoms, while considering local, semilocal, and hybrid exchange-correlation functionals. In particular, we find that <span><math><mi>O</mi></math></span>(200) grid points are sufficient to achieve an accuracy of 1 microhartree in the eigenvalues for optimized norm conserving Vanderbilt pseudopotentials spanning the periodic table from atomic number <span><math><mi>Z</mi><mo>=</mo><mn>1</mn></math></span> to 83.</div></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":"308 ","pages":"Article 109448"},"PeriodicalIF":7.2,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ComDMFT v.2.0: Fully self-consistent ab initio GW+EDMFT for the electronic structure of correlated quantum materials","authors":"Byungkyun Kang ,&nbsp;Patrick Semon ,&nbsp;Corey Melnick ,&nbsp;Mancheon Han ,&nbsp;Seongjun Mo ,&nbsp;Hoonkyung Lee ,&nbsp;Gabriel Kotliar ,&nbsp;Sangkook Choi","doi":"10.1016/j.cpc.2024.109447","DOIUrl":"10.1016/j.cpc.2024.109447","url":null,"abstract":"<div><div>ComDMFT is a parallel computational package designed to study the electronic structure of correlated quantum materials <em>from first principles</em>. Our approach is based on the combination of <em>first-principles</em> methods and dynamical mean field theories. In version 2.0, we implemented fully-diagrammatic GW+EDMFT <em>from first-principles</em> self-consistently. In this approach, correlated electrons are treated within full GW+EDMFT and the rest are treated within full-GW, seamlessly. This implementation enables the electronic structure calculation of quantum materials with weak, intermediate, and strong electron correlation without prior knowledge of the degree of electron correlation.</div></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":"308 ","pages":"Article 109447"},"PeriodicalIF":7.2,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DEMPgen: Physics event generator for Deep Exclusive Meson Production at Jefferson Lab and the EIC","authors":"Z. Ahmed ,&nbsp;R.S. Evans ,&nbsp;I. Goel ,&nbsp;G.M. Huber ,&nbsp;S.J.D. Kay ,&nbsp;W.B. Li ,&nbsp;L. Preet ,&nbsp;A. Usman","doi":"10.1016/j.cpc.2024.109444","DOIUrl":"10.1016/j.cpc.2024.109444","url":null,"abstract":"<div><div>There is increasing interest in deep exclusive meson production (DEMP) reactions, as they provide access to Generalized Parton Distributions over a broad kinematic range, and are the only means of measuring pion and kaon charged electric form factors at high <span><math><msup><mrow><mi>Q</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>. Such investigations are a particularly useful tool in the study of hadronic structure in QCD's transition regime from long-distance interactions described in terms of meson-nucleon degrees of freedom, to short-distance interactions governed by hard quark-gluon degrees of freedom. To assist the planning of future experimental investigations of DEMP reactions in this transition regime, such as at Jefferson Lab and the Electron-Ion Collider (EIC), we have written a special purpose event generator, DEMPgen. Currently, DEMPgen can generate the following reactions: <em>t</em>-channel <span><math><mi>p</mi><mo>(</mo><mi>e</mi><mo>,</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>′</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><mo>)</mo><mi>n</mi></math></span>, <span><math><mi>p</mi><mo>(</mo><mi>e</mi><mo>,</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>′</mo></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><mo>)</mo><mi>Λ</mi><mo>[</mo><msup><mrow><mi>Σ</mi></mrow><mrow><mn>0</mn></mrow></msup><mo>]</mo></math></span>, and <span><math><mover><mrow><mi>n</mi></mrow><mrow><mo>→</mo></mrow></mover><mo>(</mo><mi>e</mi><mo>,</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>′</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup><mo>)</mo><mi>p</mi></math></span> from a polarized ³He target. DEMPgen is modular in form, so that additional reactions can be added over time.</div><div>The generator produces kinematically-complete reaction events which are absolutely-normalized, so that projected event rates can be predicted, and detector resolution requirements studied. The event normalization is based on parameterizations of theoretical models, appropriate to the kinematic regime under study. Both fixed target modes and collider beam modes are supported. This paper presents the structure of the generator, the model parameterizations used for absolute event weighting, the kinematic distributions of the generated particles, some initial results using the generator, and instructions for its use.</div></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":"308 ","pages":"Article 109444"},"PeriodicalIF":7.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asparagus: A toolkit for autonomous, user-guided construction of machine-learned potential energy surfaces","authors":"Kai Töpfer ,&nbsp;Luis Itza Vazquez-Salazar ,&nbsp;Markus Meuwly","doi":"10.1016/j.cpc.2024.109446","DOIUrl":"10.1016/j.cpc.2024.109446","url":null,"abstract":"&lt;div&gt;&lt;div&gt;With the establishment of machine learning (ML) techniques in the scientific community, the construction of ML potential energy surfaces (ML-PES) has become a standard process in physics and chemistry. So far, improvements in the construction of ML-PES models have been conducted independently, creating an initial hurdle for new users to overcome and complicating the reproducibility of results. Aiming to reduce the bar for the extensive use of ML-PES, we introduce &lt;span&gt;Asparagus&lt;/span&gt;, a software package encompassing the different parts into one coherent implementation that allows an autonomous, user-guided construction of ML-PES models. &lt;span&gt;Asparagus&lt;/span&gt; combines capabilities of initial data sampling with interfaces to &lt;em&gt;ab initio&lt;/em&gt; calculation programs, ML model training, as well as model evaluation and its application within other codes such as ASE or CHARMM. The functionalities of the code are illustrated in different examples, including the dynamics of small molecules, the representation of reactive potentials in organometallic compounds, and atom diffusion on periodic surface structures. The modular framework of &lt;span&gt;Asparagus&lt;/span&gt; is designed to allow simple implementations of further ML-related methods and models to provide constant user-friendly access to state-of-the-art ML techniques.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Program summary&lt;/h3&gt;&lt;div&gt;&lt;em&gt;Program Title:&lt;/em&gt; &lt;span&gt;Asparagus&lt;/span&gt;&lt;/div&gt;&lt;div&gt;&lt;em&gt;CPC Library link to program files:&lt;/em&gt; &lt;span&gt;&lt;span&gt;https://doi.org/10.17632/9w9xw7mp2h.1&lt;/span&gt;&lt;svg&gt;&lt;path&gt;&lt;/path&gt;&lt;/svg&gt;&lt;/span&gt;&lt;/div&gt;&lt;div&gt;&lt;em&gt;Developer's repository link:&lt;/em&gt; &lt;span&gt;&lt;span&gt;https://github.com/MMunibas/Asparagus&lt;/span&gt;&lt;svg&gt;&lt;path&gt;&lt;/path&gt;&lt;/svg&gt;&lt;/span&gt;&lt;/div&gt;&lt;div&gt;&lt;em&gt;Licensing provisions:&lt;/em&gt; MIT&lt;/div&gt;&lt;div&gt;&lt;em&gt;Programming language:&lt;/em&gt; Python&lt;/div&gt;&lt;div&gt;&lt;em&gt;Supplementary material:&lt;/em&gt; Access to Documentation at &lt;span&gt;&lt;span&gt;https://asparagus-bundle.readthedocs.io&lt;/span&gt;&lt;svg&gt;&lt;path&gt;&lt;/path&gt;&lt;/svg&gt;&lt;/span&gt;&lt;/div&gt;&lt;div&gt;&lt;em&gt;Nature of problem:&lt;/em&gt; Constructing machine-learning (ML) based potential energy surfaces (PESs) for atomistic simulations is a multi-step process that requires a broad knowledge in quantum chemistry, nuclear dynamics and programming. So far, efforts mainly focused on developing and improving ML model architectures. However, there was less effort spent on providing tools for &lt;em&gt;consistent and reproducible workflows&lt;/em&gt; that support the construction of ML-PES for a variety of chemical systems for the broader science community.&lt;/div&gt;&lt;div&gt;&lt;em&gt;Solution method:&lt;/em&gt; &lt;span&gt;Asparagus&lt;/span&gt; is a program package written in Python that provides a streamlined and extensible workflow with a user-friendly command structure to support the construction of ML-PESs. This is achieved by bundling and linking data generation and sampling techniques, data management, model training, testing and evaluation tools into one modular, comprehensive workflow including interfaces to other simulation packages for the application of ","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":"308 ","pages":"Article 109446"},"PeriodicalIF":7.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Kalman filter for track reconstruction in very large time projection chambers","authors":"Federico Battisti ,&nbsp;Marian Ivanov ,&nbsp;Xianguo Lu","doi":"10.1016/j.cpc.2024.109443","DOIUrl":"10.1016/j.cpc.2024.109443","url":null,"abstract":"<div><div>This study introduces a Kalman Filter tailored for homogeneous gas Time Projection Chambers (TPCs), adapted from the algorithm utilized by the ALICE experiment. In order to describe semi-circular paths in the plane perpendicular to the magnetic field, we introduce a novel mirror rotation technique into the Kalman Filter algorithm, enabling effective tracking of trajectories of varying lengths, including those with multiple circular paths within the detector, also known as “loopers”. Demonstrated relative improvements of up to 80% in electron momentum resolution and up to 50% in muon and pion momentum resolution underscore the significance of this enhancement. Significant improvements in the reconstruction efficiency for relatively short low momentum “looper” tracks are also shown. Such advancements hold promise not only for the future of the ALICE TPC but also for neutrino high-pressure gas TPCs, where loopers become significant owing to the randomness of production points and their relatively low energies in neutrino interactions. In particular, an improvement in low energy electron reconstruction, for which the production of “looping” tracks is likely and the impact of the new algorithm is directly demonstrated, could significantly impact the quality of flux determination, which in accelerator neutrino experiments relies on the measurement of <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mi>e</mi></mrow></msub></math></span> electron scatterings.</div></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":"308 ","pages":"Article 109443"},"PeriodicalIF":7.2,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An alternative GPU acceleration for a pseudopotential plane-waves density functional theory code with applications to metallic systems","authors":"Xuejun Gong ,&nbsp;Andrea Dal Corso","doi":"10.1016/j.cpc.2024.109439","DOIUrl":"10.1016/j.cpc.2024.109439","url":null,"abstract":"<div><div>We present an alternative <span>GPU</span> acceleration for plane waves pseudopotentials electronic structure codes designed for systems that have small unit cells but require a large number of <strong>k</strong> points to sample the Brillouin zone as happens, for instance, in metals. We discuss the diagonalization of the Kohn and Sham equations and the solution of the linear system derived in density functional perturbation theory. Both problems take advantage from a rewriting of the routine that applies the Hamiltonian to the Bloch wave-functions to work simultaneously (in parallel on the <span>GPU</span> threads) on the wave-functions with different wave-vectors <strong>k</strong>, as many as allowed by the <span>GPU</span> memory. Our implementation is written in <span>CUDA Fortran</span> and makes extensive use of kernel routines that run on the <span>GPU</span> (<span>GLOBAL</span> routines) or can be called from inside the <span>GPU</span> kernel (<span>DEVICE</span> routines). We compare our method with the <span>CPUs</span> only calculation and with the approach currently implemented in <span>Quantum ESPRESSO</span> that uses <span>GPU</span> accelerated libraries for the <span>FFT</span> and for the linear algebra tasks such as the matrix-matrix multiplications as well as <span>OpenACC</span> directives for loop parallelization. We show in a realistic example that our method can give a significant improvement in the cases for which it has been designed.</div></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":"308 ","pages":"Article 109439"},"PeriodicalIF":7.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Screener and enumerator with force-field optimization (SEFFO): Algorithm for searching adsorption sites and configurations on 2D materials","authors":"Leran Lu,&nbsp;Wei Cao,&nbsp;Romain Botella","doi":"10.1016/j.cpc.2024.109440","DOIUrl":"10.1016/j.cpc.2024.109440","url":null,"abstract":"<div><div>With the increasing attention to 2D materials for photocatalytic applications, as well as to data science, there is a need for high-throughput computation of adsorption states for experimentally or theoretically discovered structures in order to study (photo-) catalytic mechanism. Despite numerous progresses in high-throughput methods for adsorption study, a general search algorithm is lacking. In this work, SEFFO (Screener and Enumerator with Force-Field Optimization) algorithm is developed for the automation of adsorption study on 2D material surface. Graph theory is utilized to create the descriptors of the adsorption configurations, which are later input for geometry construction by numerical optimization. The configuration screening process is combining the use of graphs with structural similarity comparison of configurations density functional theory (DFT) produced configurations. The algorithm is validated through four case studies, involving water and carbon dioxide molecules as adsorbates, molybdenum sulfide and carbon nitride as substrate counterparts. The results are consistent with literature while proposing alternative configurations. Additionally, SEFFO can show the evolution between configurations during the process. This method enables the high throughput study of adsorption behavior on 2D materials, and paves the way for future surface studies involving other substrate/adsorbates pairs.</div></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":"308 ","pages":"Article 109440"},"PeriodicalIF":7.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"BO-KM: A comprehensive solver for dispersion relation of obliquely propagating waves in magnetized multi-species plasma with anisotropic drift kappa-Maxwellian distribution","authors":"Wei Bai ,&nbsp;Huasheng Xie ,&nbsp;Chenchen Wu ,&nbsp;Yanxu Pu ,&nbsp;Pengcheng Yu","doi":"10.1016/j.cpc.2024.109434","DOIUrl":"10.1016/j.cpc.2024.109434","url":null,"abstract":"<div><div>The observation of superthermal plasma distributions in space reveals a multitude of distributions with high-energy tails, and the kappa-Maxwellian distribution is a type of non-Maxwellian distribution that exhibits this characteristic. However, accurately determining the multiple roots of the dispersion relation for superthermal plasma waves propagating obliquely presents a challenge. To tackle this issue, we have developed a comprehensive solver, BO-KM, utilizing an innovative numerical algorithm that eliminates the need for initial value iteration. The solver offers an efficient approach to simultaneously compute the roots of the kinetic dispersion equation for oblique propagation in magnetized plasmas. It can be applied to magnetized superthermal plasma with multi-species, characterized by anisotropic drifting kappa-Maxwellian, bi-Maxwellian distributions, or a combination of the two. The rational and J-pole Padé expansions of the dispersion relation are equivalent to solving a linear system's matrix eigenvalue problem. This study presents the numerical findings for kappa-Maxwellian plasmas, bi-Maxwellian plasmas, and their combination, demonstrating the solver's outstanding performance through benchmark analyses.</div></div><div><h3>Program summary</h3><div><em>Program Title:</em> BO-KM</div><div><em>CPC Library link to program files:</em> <span><span>https://doi.org/10.17632/pr9cvjrvfv.1</span><svg><path></path></svg></span></div><div><em>Licensing provisions:</em> BSD 3-clause</div><div><em>Programming language:</em> Matlab</div><div><em>Nature of problem:</em> To efficiently solve for multiple roots of the kinetic dispersion relation in superthermal plasma distributions with high-energy tails observed in space, we have developed BO-KM, a novel and comprehensive solver that employs a unified framework for computing uprathermal (or thermal) waves and instabilities. This solver is applicable to magnetized multi-species collisionless plasmas with anisotropic drift kappa-Maxwellian, bi-Maxwellian distributions, or a combination of both. Furthermore, BO-KM incorporates a submodule dedicated to the perpendicular propagation dispersion relation of bi-Kappa plasmas, thereby significantly improving computational efficiency at high <em>κ</em> values.</div><div><em>Solution method:</em> The method converts the kinetic plasma dispersion relation based on rational expansion (for the kappa-Maxwellian model) and J-pole Padé expansion (for the bi-Maxwellian model) into an equivalent linear eigenvalue system. This transformation effectively turns the root-finding task into an eigenvalue problem, enabling the simultaneous determination of roots using standard eigenvalue libraries.</div><div><em>Additional comments including restrictions and unusual features:</em> Kinetic relativistic effects are not included in the present version yet.</div></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":"307 ","pages":"Article 109434"},"PeriodicalIF":7.2,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TorchAmi: Generalized CPU/GPU implementation of algorithmic matsubara integration","authors":"M.D. Burke ,&nbsp;J.P.F. LeBlanc","doi":"10.1016/j.cpc.2024.109437","DOIUrl":"10.1016/j.cpc.2024.109437","url":null,"abstract":"<div><div>We present <span>torchami</span>, an advanced implementation of algorithmic Matsubara integration (AMI) that utilizes <span>pytorch</span> as a backend to provide easy parallelization and GPU support. AMI is a tool for analytically resolving the sequence of nested Matsubara integrals that arise in virtually all Feynman perturbative expansions. In this implementation we present a new AMI algorithm that creates a more natural symbolic representation of the Feynman integrands. In addition, we include peripheral tools that allow for import and labeling of simple graph structures and conversion to <span>torchami</span> input. The code is written in c++ with python bindings provided.</div></div><div><h3>Program summary</h3><div><em>Program Title:</em> torchami</div><div><em>CPC Library link to program files:</em> <span><span>https://doi.org/10.17632/m79hnngy8s.1</span><svg><path></path></svg></span></div><div><em>Developer's repository link:</em> <span><span>https://github.com/mdburke11/torchami/releases/tag/v1.0</span><svg><path></path></svg></span></div><div><em>Licensing provisions:</em> GPLv3</div><div><em>Programming language:</em> <span>C++, python</span></div><div><em>Nature of problem:</em> Feynman diagrams are pictorial representations of perturbative expansions often formulated in the imaginary frequency/time axis and involve a high-dimensional sequence of nested integral over spatial and temporal degrees of freedom.</div><div><em>Solution method:</em> <span>torchami</span> provides a framework to symbolically generate and store the analytic solution to the temporal Matsubara sums through repeated application of multipole residue theorems. The solutions are stored using a tree structure for arbitrary products and sums of Fermi/Bose functions, and the evaluation functions provide both CPU and GPU support with automatic parallelization for batch sampling problems.</div><div><em>Additional comments including restrictions and unusual features:</em> Requires <span>C++17</span> standard, the boost graph library, as well as <span>pytorch</span>.</div></div><div><h3>References</h3><div><ul><li><span>[1]</span><span><div>Amir Taheridehkordi, S. H. Curnoe, and J. P. F. LeBlanc, Algorithmic Matsubara integration for Hubbard-like models, Phys. Rev. B 99 035120 (2019).</div></span></li><li><span>[2]</span><span><div>H. Elazab, B. D. E. McNiven, and J. P. F. LeBlanc, LIBAMI: Implementation of algorithmic Matsubara integration, Computer Physics Communications 280, 108469 (2022)</div></span></li></ul></div></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":"308 ","pages":"Article 109437"},"PeriodicalIF":7.2,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}