Molecular Orbital Simulations of Metal 1s2p Resonant Inelastic X-ray Scattering
Molecular Orbital Simulations of Metal 1s2p Resonant Inelastic X-ray Scattering
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DOI：
10.1021/acs.jpca.6b05139
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发表时间：
2016-07-28
影响因子：
2.9
通讯作者：
Lundberg, Marcus
中科院分区：
文献类型：
--
作者：
Guo, Meiyuan;Kallman, Erik;Lundberg, Marcus
对于第一行过渡金属，高分辨率的三维电子结构信息可以使用共振非弹性X射线散射（RIXS）。在硬X射线区域，K前沿（1 s-> 3d）激发之后可以监测偶极允许的K α（2 p-> 1 s）或K β（3 p-> 1 s）发射，标记为1 s2 p或1 s3 p RIXS的过程。在这里，限制活性空间（RAS）的方法，这是一种分子轨道方法，用于研究硬X射线RIXS过程的第一次。这是通过在活性空间的不同分区中包括两组核心轨道来实现的。使用波矢量的一阶和二阶展开计算跃迁强度，包括但不限于电偶极子和四极子。该方法的准确性进行了测试的铁六氰化物[Fe（CN）（6）]（n-）在亚铁和铁的氧化态的1 s2 p RIXS。RAS模拟准确地描述了多重态结构和2 p和3d自旋轨道耦合对能量和选择规则的作用。与实验结果相比，[Fe（CN）（6）]（3-）两个共振态的相对能量在入射能量和能量转移方向上均偏离了0.2eV，[Fe（CN）（6）]（4-）的多重态分裂在0.1eV内重现.这些值与价激发的预期值相似。这一发展开启了溶液催化剂和酶系统硬X射线散射过程的建模。
For first-row transition metals, high-resolution 3d electronic structure information can be obtained using resonant inelastic X-ray scattering (RIXS). In the hard X-ray region, a K pre-edge (1s -> 3d) excitation can be followed by monitoring the dipole-allowed K alpha (2p -> 1s) or K beta (3p -> 1s) emission, processes labeled 1s2p or 1s3p RIXS. Here the restricted active space (RAS) approach, which is a molecular orbital method, is used for the first time to study hard X-ray RIXS processes. This is achieved by including the two sets of core orbitals in different partitions of the active space. Transition intensities are calculated using both first- and second-order expansions of the wave vector, including, but not limited to, electric dipoles and quadrupoles. The accuracy of the approach is tested for 1s2p RIXS of iron hexacyanides [Fe(CN)(6)](n-) in ferrous and ferric oxidation states. RAS simulations accurately describe the multiplet structures and the role of 2p and 3d spin-orbit coupling on energies and selection rules. Compared to experiment, relative energies of the two [Fe(CN)(6)](3-) resonances deviate by 0.2 eV in both incident energy and energy transfer directions, and multiplet splittings in [Fe(CN)(6)](4-) are reproduced within 0.1 eV. These values are similar to what can be expected for valence excitations. The development opens the modeling of hard X-ray scattering processes for both solution catalysts and enzymatic systems.