Quantum chemical investigations of surface chemistry with a hierarchy of cluster models

印第安纳州大学的Krishnan Raghavachari得到了理论和计算化学项目的支持，开展研究，旨在开发和应用一套分层计算模型，用于各种材料表面化学的量子化学研究。 首先，将开发非常成功的G3热化学系列，并将其应用于缺乏精确计算方法的涉及较重主族以及过渡金属的材料。 其次，将开发具有非氢终止方案（包括终止原子上的有效势）的新型团簇模型，以克服以前使用的氢原子终止方案所带来的限制。 第三，将开发用于精确处理嵌入式团簇的新方法，包括不同区域之间的电子耦合。 新开发的方法将应用于的化学系统包括：（1）硅界面处的自由基化学，（2）硅表面上的金属氧化物原子层沉积（ALD），（3）化合物半导体界面上的化学气相沉积（CVD），（4）二氧化硅纳米颗粒的表面化学，（5）钒氧化物表面的催化机理。计算机能力的不断提高将很快产生前所未有的预测能力。 该项目将导致对许多重要材料类别的基本见解，并导致推动未来技术进步的新想法。 计算材料化学，作为一个快速发展的领域，预计将吸引大量的学生的兴趣和机会。

Krishnan Raghavachari of Indiana University is supported by the Theoretical and Computational Chemistry Program to carry out research that aims to develop and apply a set of hierarchical computational models for use in quantum chemical studies of the surface chemistry of a variety of materials. First, the highly successful G3 thermochemical series will be developed and applied to materials involving heavier main-group as well as transition metals where methodologies for accurate calculations are lacking. Second, novel cluster models with non-hydrogen termination schemes including effective potentials on the terminating atoms will be developed to overcome the limitations arising from hydrogen atom termination schemes used previously. Third, new methods for the accurate treatment of embedded clusters including electronic coupling between the different regions will be developed. The chemical systems to which the newly developed methods will be applied include: (1) radical chemistry at silicon interfaces, (2) metal oxide atomic layer deposition (ALD) on silicon surfaces, (3) chemical vapor deposition (CVD) on compound semiconductor interfaces, (4) surface chemistry of silica nanoparticles, and (5) catalytic mechanisms on vanadium oxide surfaces.The continued increase in the power of computers will soon yield unprecedented predictive capability. This project will lead to fundamental insights concerning many important classes of materials, and as well lead to novel ideas fueling future technological advances. Computational materials chemistry, as a rapidly expanding field, is expected to attract a great deal of student interest and opportunity.