ITR: Large-scale, Grid-enabled Gaussian Orbital Implementation of Current Density and Spin Density Functional Theory for Ordered Systems

ITR：有序系统的电流密度和自旋密度泛函理论的大规模、支持网格的高斯轨道实现

• 批准号: 0218957
• 负责人: Samuel Trickey
• 金额: $ 44.8万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-15 至 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0218957&HistoricalAwards=false
• 关键词: ITR; Large; scale; Grid; enabled

This award is made in response to a proposal submitted to the Information Technology Research (ITR) Initiative. The objective of the research is to design, develop and implement, test, and apply major enhancements of the high-performance, all-electron, full-potential, relativistic gaussian-basis density functional theory (DFT) code for crystals, slabs, and periodic polymers called "GTOFF" (Gaussian Type Orbitals for Fitting Functions). The goals are (a) to include imposed magnetic fields as a major extension of materials-specific DFT prediction and interpretation of periodic systems; (b) make major speed-ups to handle much larger systems, e.g., nano-featured surfaces, ordered hard-soft interfaces; (c) introduce algorithms and data structures that will enable treatment of extremely large and/or complicated systems via grid technologies; (d) substantially improve the capability for revising and/or adding methods and capabilities to do more science.A major advantage of GTOFF is use of the same kinds of basis sets and procedures as the majority of molecular codes. It thus provides a seamless way to study chemically differentiated systems, from constituent atoms to molecule, cluster or nanoparticle to crystal or slab, including cluster-surface interactions and nano-featured surfaces.Successful, robust spin DFT algorithms in GTOFF will be reimplemented in C++ (from Fortran 77) to achieve modularity, manageability, and extendability now lacking. Those algorithms include generalized Ewald techniques to sum long-ranged contributions (rather than more common, sometimes less reliable multipole expansions), variational Coulomb fitting to eliminate 4-center integrals, fitting of exchange-correlation densities to fitted densities (eliminates extra sums over Brillouin Zone points), accuracy-conserving constraints on fittings, Douglas-Kroll-Hess relativity (including spin-orbit contributions). GTOFF now is serial. The redsign/reimplementation will exploit known parallelism opportunities as well as provide grid enablement. Current-density Functional Theory (C-DFT) will be built into the new design as a major extension to provide predictive treatment of materials at high magnetic field.The planned effort involves several major components: (a) redesign (not mere transcription) of the present GTOFF to take advantage of modern programming practices, construct a proper organization for parallelism (with hooks for MPI), include algorithms and data structures for grid-enabled computing; (b) design of gaussian orbital algorithms and techniques for current DFT; (c) re-implementation in C++ of the redesigned GTOFF for spin DFT; (d) extensive testing to assure reproducibility in serial mode, then in parallel; (e) implementation and testing of current DFT in the new GTOFF; (f) grid-enablement, including (but not limited to) interpolation among precalculated integral arrays, interpolation among approximate energy calculations, and energy gradient calculations direct from density fitting.The grant will provide support for a postdoctoral associate and graduate students who will will learn programming skills in addition to the fundamental chemistry and physics necessary to develop and apply the GTOFF codes.%%% This award is made in response to a proposal submitted to the Information Technology Research (ITR) Initiative. The objective of the research is to design, develop and implement, test, and apply major enhancements of the high-performance, all-electron, full-potential, relativistic gaussian-basis density functional theory (DFT) code for crystals, slabs, and periodic polymers called "GTOFF" (Gaussian Type Orbitals for Fitting Functions). The goals are (a) to include imposed magnetic fields as a major extension of materials-specific DFT prediction and interpretation of periodic systems; (b) make major speed-ups to handle much larger systems, e.g., nano-featured surfaces, ordered hard-soft interfaces; (c) introduce algorithms and data structures that will enable treatment of extremely large and/or complicated systems via grid technologies; (d) substantially improve the capability for revising and/or adding methods and capabilities to do more science.A major advantage of GTOFF is use of the same kinds of basis sets and procedures as the majority of molecular codes. It thus provides a seamless way to study chemically differentiated systems, from constituent atoms to molecule, cluster or nanoparticle to crystal or slab, including cluster-surface interactions and nano-featured surfaces. The grant will provide support for a postdoctoral associate and graduate students who will will learn programming skills in addition to the fundamental chemistry and physics necessary to develop and apply the GTOFF codes.***

该奖项是为了响应提交给信息技术研究（ITR）倡议的提案。 该研究的目标是设计，开发和实施，测试和应用高性能，全电子，全电势，相对论高斯基密度泛函理论（DFT）代码的主要增强功能，用于晶体，平板和周期性聚合物，称为“GTOFF”（高斯型轨道拟合函数）。 目标是（a）将施加的磁场作为特定材料DFT预测和周期系统解释的主要扩展;（B）进行重大加速以处理更大的系统，例如，纳米特征表面、有序的硬-软界面;（c）引入算法和数据结构，其将使得能够通过网格技术处理极大和/或复杂的系统;（d）实质上提高修改和/或添加方法的能力和进行更多科学研究的能力。 因此，它提供了一个无缝的方式来研究化学差异化的系统，从组成原子到分子，簇或纳米颗粒晶体或slab，包括簇表面相互作用和nano-featured surface.Successful，强大的自旋DFT算法在GTOFF将重新实现在C++（从Fortran 77），以实现模块化，可扩展性，和可扩展性，现在缺乏。 这些算法包括广义Ewald技术来计算长程贡献（而不是更常见的，有时不太可靠的多极展开），变分库仑拟合以消除4中心积分，将交换相关密度拟合到拟合密度（消除布里渊区点的额外总和），对拟合的精度保持约束，道格拉斯-克罗尔-赫斯相对论（包括自旋轨道贡献）。 GTOFF现在是串行的。 redsign/重新实现将利用已知的并行机会，并提供网格支持。 电流密度泛函理论（C-DFT）将作为一个主要的扩展，被纳入新的设计中，以提供高磁场下材料的预测处理。计划的工作涉及几个主要组成部分：（a）重新设计（不仅仅是转录）目前的GTOFF，以利用现代编程实践，构建一个适当的组织并行（与MPI挂钩），包括网格计算的算法和数据结构;（B）为当前DFT设计高斯轨道算法和技术;（c）用C++重新实现自旋DFT的重新设计的GTOFF;（d）广泛的测试，以确保串行模式的再现性，然后并行;（e）在新的GTOFF中实施和测试当前的DFT;（f）电网启用，包括（但不限于）预先计算的积分阵列之间的内插，近似能量计算之间的内插，和能量梯度计算直接从密度拟合。赠款将提供支持博士后助理和研究生谁将学习编程技能，除了必要的基础化学和物理开发和应用GTOFF代码。 该奖项是为了响应提交给信息技术研究（ITR）倡议的提案。 该研究的目标是设计，开发和实施，测试和应用高性能，全电子，全电势，相对论高斯基密度泛函理论（DFT）代码的主要增强功能，用于晶体，平板和周期性聚合物，称为“GTOFF”（高斯型轨道拟合函数）。 目标是（a）将施加的磁场作为特定材料DFT预测和周期系统解释的主要扩展;（B）进行重大加速以处理更大的系统，例如，纳米特征表面、有序的硬-软界面;（c）引入算法和数据结构，其将使得能够通过网格技术处理极大和/或复杂的系统;（d）实质上提高修改和/或添加方法的能力和进行更多科学研究的能力。 因此，它提供了一种无缝的方式来研究化学差异化系统，从组成原子到分子，簇或纳米颗粒到晶体或板，包括簇表面相互作用和纳米特征表面。 该补助金将为博士后助理和研究生提供支持，他们将学习编程技能，以及开发和应用GTOFF代码所需的基本化学和物理。