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首页> 外文期刊>Physical review >Role of electronic friction during the scattering of vibrationally excited nitric oxide molecules from Au(111)
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Role of electronic friction during the scattering of vibrationally excited nitric oxide molecules from Au(111)

机译：电子摩擦在振动激发的一氧化氮分子从Au（111）散射中的作用

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Some time ago, it has been observed that vibrationally highly excited NO(v) molecules (with typical vibrational quantum numbers v ≈ 15) lose substantial amounts of vibrational energy when scattering off a Au(111) surface [H. Huang, C. Rettner, D. Auerbach, and A. Wodtke, Science 290, 111 (2000)]. This has been interpreted as a sign for the breakdown of the Born-Oppenheimer approximation due to vibration-electron coupling. It has been argued that this process cannot be understood on the basis of single-quantum transitions which are typical for "electronic friction" models based on a perturbative treatment of weak vibration-electron couplings. Rather, multiple-quanta transitions characteristic for strong nonadiabatic effects are needed according to recent classical surface hopping calculations involving multiple potential-energy surfaces and model Hamiltonians [N. Shenvi, S. Roy, and J. C. Tully, Science 326, 829 (2009)]. Here we address the importance and magnitude of electronic friction for NO@Au(111) by using fully quantum-mechanical, parameter-free first-principles theories in reduced dimensions. Periodic density-functional theory calculations are performed to obtain a ground-state potential-energy surface along the desorption and NO-vibration coordinates, and coordinate-resolved, finite NO vibrational lifetimes due to vibration-electron coupling. Using this input, the scattering event is modeled by open-system density-matrix theory in the frame of the coupled-channel-density-matrix method, which allows for the inclusion of energy relaxation of the scattering NO molecules. It is found that within this model at least, electronic friction accounts for the observed vibrational deactivation of NO scattering from gold.
机译：一段时间以前，已经观察到，当从Au（111）表面[H]散射时，振动高度激发的NO（v）分子（具有典型的振动量子数v≈15）会损失大量的振动能。 Huang，C. Rettner，D. Auerbach，and A.Wodtke，Science 290，111（2000）]。这被解释为由于振动-电子耦合而使Born-Oppenheimer近似分解的标志。有人认为，不能基于对弱振动-电子耦合进行微扰处理的“电子摩擦”模型所特有的单量子跃迁来理解该过程。相反，根据最近涉及多个势能表面和模型哈密顿量的经典表面跳变计算，需要具有强非绝热效应的多量子跃迁特征。 Shenvi，S。Roy和J.C. Tully，《科学》 326，829（2009）。在这里，我们通过使用尺寸减小的完全量子力学，无参数的第一原理理论来解决NO @ Au（111）电子摩擦的重要性和大小。进行周期性的密度泛函理论计算，以获得沿解吸和NO振动坐标的基态势能表面，以及由于振动-电子耦合而坐标解析的有限NO振动寿命。使用此输入，在耦合通道密度矩阵方法的框架内，通过开放系统密度矩阵理论对散射事件进行建模，该方法允许包含散射NO分子的能量弛豫。发现至少在该模型内，电子摩擦解释了观察到的金NO散射的振动失活。

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