Development of Computer Algorithms for Density Functional Theory Simulations and Applications to Crystal Growth

Hannes Jonsson获得了理论和计算化学项目的资助，继续他在密度泛函理论模拟和半导体晶体生长应用的计算机算法开发方面的研究。Jonsson将并行化他自己的方法来寻找最小能量路径和过渡态激活势垒。他还将研究包括非调和性在内的自由能势垒，以及随系统大小线性扩展的算法。他的应用将集中在通过计算工业相关系统（如硅和碳化硅表面、锗硅界面和二氧化硅覆盖层）的吸附原子扩散速率和表面簇形成速率来解释当前的成像实验。现代密度泛函理论方法将被发展并用于研究各种具有重要技术意义的表面生长机制。特别是，这些方法将被扩展到能够在新的和正在出现的大规模并行计算机上研究更大、更复杂的材料模型。这些方法涉及对半导体表面上许多复杂原子尺度过程的精确能量学的复杂评估。

Hannes Jonsson is supported by a grant from the Theoretical and Computational Chemistry Program to continue his research in the development of computer algorithms for density functional theory simulations and applications to semiconductor crystal growth. Jonsson will parallelize his own methods for finding minimum energy paths and transition state activation barriers. He will also investigate free energy barriers which include anharmonicity, and algorithms which scale linearly with system size. His applications will focus on interpretation of current imaging experiments by calculating adatom diffusion rates and surface cluster formation rates for industrially relevant systems such as silicon and silicon carbide surfaces, germanium-silicon interfaces, and silicon dioxide overlayers. Modern density functional theoretical methods will be developed and used to study a variety of surface growth mechanisms of technological importance. In particular these methods will be extended to enable the study of larger, more complex models of materials on new and emerging massively parallel computers. The methods involve the sophisticated evaluation of accurate energetics for a number of complex atomic-scale processes on semiconductor surfaces.