A Symmetry-Based Approach to Minimum Energy Pathways

基于对称性的最小能量路径方法

• 批准号: 1807768
• 负责人: Venkatraman Gopalan
• 金额: $ 41.99万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1807768&HistoricalAwards=false
• 关键词: Symmetry; Based; Approach; Minimum; Energy

Non-technical description: Symmetry is a powerful tool in all of physical sciences. Distortions, often a collection of atomic trajectories, are important for understanding a range of kinetic materials processes where atoms move under external stimuli such as fields, temperature, and stress. Predicting which path a material would take in undergoing a distortion is important for any application which involves such atomic motion. However, predicting such paths, called minimum energy pathways (MEPs), is currently stochastic in nature, and one can never be sure of the final results. This project aims at developing a new symmetry-based framework and computational tools through the introduction of new ideas such as distortion-reversal symmetry and distortion groups; it significantly improves the speed, numerical accuracy, and the comprehensive nature of search for such paths. Experimental verification of the theory predictions is the other aspect of this research. The growing need for educational training in computation materials research is being addressed with hands-on workshops in density-functional theory, active mentoring of undergraduates in research including women and underrepresented groups, and through active participation in STEM Academy of the Upward Bound Math and Science Program, as well as Penn State Millennium Scholars Program that attracts and guides talented STEM students to the undergraduate program. Technical description: This is an integrated theory-experimental proposal that develops new symmetry ideas and computational tools to explore minimum energy pathways (MEPs) for distortions, and more specifically, for ferroelectric domain switching and domain wall motion. The MEPs are computed by the Nudged Elastic Band method (NEB); however, it currently relies on a combination of stochastic process and user intuition to construct initial paths. The principal investigators are focused on the concept of the symmetry group of a path and are develop a code (to be made publicly available when ready) to implement these ideas in Quantum Espresso, an open-source density functional theory (DFT) software. Three model system classes are picked, namely, in simple perovskites, in layered oxides, and in multiferroics, to make predictions. The predicted MEPs with this approach are tested using the experimental techniques that push in-situ dynamics with 2-5 picometers metrology in electron microscopy, and ultrafast electron diffraction microscopy techniques.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术描述：对称是所有物理科学中的强大工具。扭曲，通常是原子轨迹的集合，对于理解一系列动力学材料过程很重要，在这些动力学材料过程中，原子在外部刺激（例如田间，温度和压力）下移动。预测材料在经历变形时所采取的路径对于任何涉及这种原子运动的应用都很重要。但是，预测这样的路径（称为最小能量途径（MEP））本质上是随机的，并且永远无法确定最终结果。该项目旨在通过引入诸如失真反转对称和失真组等新思想来开发新的基于对称性的框架和计算工具；它显着提高了搜索此类路径的速度，数值准确性和全面性质。理论预测的实验验证是这项研究的另一个方面。 The growing need for educational training in computation materials research is being addressed with hands-on workshops in density-functional theory, active mentoring of undergraduates in research including women and underrepresented groups, and through active participation in STEM Academy of the Upward Bound Math and Science Program, as well as Penn State Millennium Scholars Program that attracts and guides talented STEM students to the undergraduate program.技术描述：这是一项综合理论实验建议，它开发了新的对称思想和计算工具，以探索扭曲的最小能量途径（MEP），更具体地说，是针对铁电域切换和域壁运动的。 MEP通过裸露的弹性带方法（NEB）计算；但是，目前，它依赖于随机过程和用户​​直觉的组合来构建初始路径。首席研究人员专注于路径对称组的概念，并正在开发代码（准备就绪时公开提供），以在Quantum Espresso（一种开源的密度功能理论（DFT）软件）中实施这些想法。选择三个模型系统类别，即，在简单的钙壶中，分层的氧化物和多表色中选择了三个模型类别，以做出预测。使用该方法的预测MEP使用实验技术进行了测试，该实验技术在电子显微镜中以2-5个近距离计量学和超快电子衍射显微镜技术来推动原位动力学。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识优点和广泛的crietia crietia crietia criperia criperia criperia criperia criperia criperia crietia crietia crietia crietia crietia cristria criperia criperia criperia criperia recectia recectia rection the奖项。

项目成果

Understanding the influence of defects and surface chemistry on ferroelectric switching: a ReaxFF investigation of BaTiO3

• DOI: 10.1039/c9cp02955a
• 发表时间: 2019-09-07
• 期刊: PHYSICAL CHEMISTRY CHEMICAL PHYSICS
• 影响因子: 3.3
• 作者: Akbarian, Dooman;Yilmaz, Dundar E.;van Duin, Adri C. T.
• 通讯作者: van Duin, Adri C. T.

Shear-induced unidirectional deposition of bacterial cellulose microfibrils using rising bubble stream cultivation

• DOI: 10.1016/j.carbpol.2020.117328
• 发表时间: 2021-01-09
• 期刊: CARBOHYDRATE POLYMERS
• 影响因子: 11.2
• 作者: Chae, Inseok;Bokhari, Syed M. Q.;Kim, Seong H.
• 通讯作者: Kim, Seong H.

High-Pressure Synthesis and Ferrimagnetism of Ni 3 TeO 6 -Type Mn 2 ScMO 6 (M = Nb, Ta)

Ni 3 TeO 6 型Mn 2 ScMO 6 (M = Nb, Ta)的高压合成及其亚铁磁性

• DOI: 10.1021/acs.inorgchem.9b02468
• 发表时间: 2019
• 期刊: Inorganic Chemistry
• 影响因子: 4.6
• 作者: Feng, Hai L.;Deng, Zheng;Croft, Mark;Lapidus, Saul H.;Zu, Rui;Gopalan, Venkatraman;Grams, Christoph P.;Hemberger, Joachim;Liu, Sizhan;Tyson, Trevor A.
• 通讯作者: Tyson, Trevor A.

Wedge reversion antisymmetry and 41 types of physical quantities in arbitrary dimensions

楔形反转反对称性和任意维度的41种物理量

• DOI: 10.1107/s205327332000217x
• 发表时间: 2020
• 期刊: Acta Crystallographica Section A Foundations and Advances
• 作者: Gopalan, Venkatraman

Discovering minimum energy pathways via distortion symmetry groups

• DOI: 10.1103/physrevb.98.085107
• 发表时间: 2018-04
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Jason M. Munro;H. Akamatsu;Haricharan Padmanabhan;Vincent S Liu;Yin Shi;Long-Qing Chen;B. K. Vanleeuwen-B.-K.