Exploring potential energy surfaces for strong field chemistry, ion dynamics and bio-organic chemistry

H.韦恩州立大学的Bernhard Schlegel获得了化学系化学理论、模型和计算方法项目的奖励，以探索强场化学、从头算分子动力学、生物有机系统和反应路径优化方面的项目。 解释，集成的时间依赖组态相互作用（TD-CI）和密度泛函理论将进行比较建模分子与短，强激光脉冲相互作用。将评估模拟强场电离的不同方法。 TD-CI模拟与场相关的状态和改进的方法，在强磁场中整合从头算经典轨迹。 标准和远程校正泛函将在强激光场的经典轨迹进行比较。 这些从头算分子动力学方法将用于研究强场碎裂中质子的动能分布，以及分子与强激光场相互作用中H（+）的迁移和H3（+）的形成。 生物有机系统的研究将包括鸟嘌呤氧化途径中中间体的氧化还原电位，环境对核碱基pKa和氧化还原电位的影响，鸟嘌呤-胸腺嘧啶交联和金属促进的鸟嘌呤氧化。 为了支持这些研究，将开发新的方法来优化反应路径，通过接缝和锥形交叉点的反应路径，以及分叉势能面的反应路径。理解分子动力学和探索反应路径是化学中的关键挑战。强场化学和阿秒科学通过使用短的强激光脉冲来探测结构和反应性来解决这些挑战。 Schlegel教授和他的团队正在开发新的方法来模拟分子在这些极端条件下的行为。生物有机系统的选定研究包括与毒性，诱变和癌症有关的DNA碱基的性质和反应性。 为了支持这些研究，研究人员正在开发探索势能面上反应路径的新方法，这将有利于利用分子轨道计算的许多化学领域。

H. Bernhard Schlegel of Wayne State University is supported by an award from the Chemical Theory, Models and Computational Methods program in the Chemistry Division to explore projects in strong field chemistry, ab initio molecular dynamics, bio-organic systems, and reaction path optimization. Explicitly, integration of time dependent configuration interaction (TD-CI) and density functional theory will be compared for modeling molecules interacting with short, intense laser pulses. Different methods for simulating strong field ionization will be assessed. TD-CI simulations with field-dependent states and improved methods for integrating ab initio classical trajectories in strong fields will be developed. Standard and long-range corrected functionals will be compared for classical trajectories in strong laser fields. These ab initio molecular dynamics methods will be used to study the kinetic energy distribution of protons in strong field fragmentations, and H(+) migration and H3(+) formation from molecules interacting with intense laser fields. Studies of bio-organic systems will include redox potentials of intermediates in guanine oxidation pathways, environmental effects on nucleobase pKa's and redox potentials, guanine-thymine crosslinks and metal-promoted oxidation of guanine. To support these studies, new methods will be developed for reaction path optimization, reaction paths through seams and conical intersections, and reaction paths for bifurcating potential energy surfaces.Understanding molecular dynamics and exploring reaction pathways are key challenges in chemistry. Strong field chemistry and attosecond science address these challenges by using short intense laser pulses to probe structure and reactivity. Professor Schlegel and his team are developing new methods for simulating the behavior of molecules under these extreme conditions. The selected studies of bio-organic systems include properties and reactivity of DNA bases related to toxicity, mutagenesis and cancer. To support these studies, the researchers are developing new methods for exploring reaction paths on potential energy surfaces that will benefit many areas of chemistry which utilize molecular orbital calculations.