Full Configuration Interaction Quantum Monte Carlo: from Molecules to Materials

全配置交互量子蒙特卡罗：从分子到材料

• 批准号: EP/I014624/1
• 负责人: Ali Alavi
• 金额: $ 18.12万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FI014624%2F1
• 关键词: Full; Configuration; Interaction; Quantum; Monte

The fundamental equation governing the properties of atoms, molecules and materials is the many-electron Schr\ odinger equation, whose solution gives the energy of the system under consideration, by solving for the correlated motions of the constituent electrons. Accounting for this correlation has proven to be both essential for useful modelling of materials, as well as extremely difficult to calculate. In this proposal, we will develop a radically new approach to this problem based an algorithm which propagates an evolving distribution of walkers which inhabit an abstract space of states (Slater determinants) which are able to account for this correlation.The algorithm is a remarkably simple set of rules (but specially devised), akin to a Game of Life. This algorithm has been shown by the PI to work efficiently for isolated molecules, extending the range of FCI-level calculations by many orders of magnitude. The proposal here is to extend FCIQMC for an infinitely repeating system, which can be used to model a material such as diamond or graphite. This extension requires the method to be extended in a fundamental way, to allow for complex rather than purely real walkers. A method to do this is proposed in the Case for Support. If successful, this method could transform the field of modelling of materials, in that it would give access, for the first time, a way to compute the correlation energy without the imposition of uncontrolled approximations. In developing experience with this new technique, we hope one day to be able to solve some of the problems posed by the rapidly developing field of correlated materials, which have so far proven impervious to existing methods.

控制原子、分子和材料性质的基本方程是多电子薛定谔方程，其解通过求解组成电子的相关运动来给出所考虑系统的能量。考虑到这种相关性已被证明对于材料的有用建模是必不可少的，并且非常难以计算。在这个建议中，我们将开发一个全新的方法来解决这个问题的基础上，传播一个不断发展的分布的步行者居住在一个抽象的空间的状态（斯莱特决定因素），这是能够说明这种相关性的算法是一个非常简单的规则集（但专门设计），类似于一个游戏的生活。PI已经证明这种算法对孤立分子有效，将FCI水平计算的范围扩展了许多数量级。这里的建议是将FCIQMC扩展为无限重复系统，该系统可用于模拟金刚石或石墨等材料。这种扩展要求该方法以基本的方式进行扩展，以允许复杂的而不是纯粹的真实的步行者。在支持案例中提出了一种方法。如果成功，这种方法可以改变材料建模领域，因为它将首次提供一种计算相关能量的方法，而无需强加不受控制的近似值。在开发这种新技术的经验中，我们希望有一天能够解决快速发展的相关材料领域所带来的一些问题，这些问题迄今为止已被证明是现有方法无法解决的。

项目成果

NECI: N-Electron Configuration Interaction with emphasis on state-of-the-art stochastic methods

NECI：N-电子构型相互作用，重点是最先进的随机方法

• DOI: 10.48550/arxiv.2006.14956
• 发表时间: 2020
• 作者: Guther K

An explicitly correlated approach to basis set incompleteness in Full Configuration Interaction Quantum Monte Carlo

全配置交互量子蒙特卡罗中基组不完整性的显式相关方法

• DOI: 10.48550/arxiv.1208.0980
• 发表时间: 2012
• 作者: Booth G