A first-principles approach to the calculation of the on-site zero-field splitting in polynuclear transition metal complexes.
A first-principles approach to the calculation of the on-site zero-field splitting in polynuclear transition metal complexes.
复制标题
计算多核过渡金属配合物中现场零场分裂的第一原理方法。
DOI：
10.1021/ic502081c
复制
发表时间：
2014
影响因子：
4.6
通讯作者：
F. Neese
中科院分区：
文献类型：
--
作者：
M. Retegan;N. Cox;D. Pantazis;F. Neese
多核过渡金属配合物的电子顺磁共振光谱的解释，从每个顺磁中心的个人贡献，可以大大方便的理论方法，使当地光谱参数的可靠预测的可用性。在这项工作中，我们报告了一种方法，使应用多参考从头计算方法计算的局部零场分裂张量，在自旋哈密顿交换耦合系统的高核性的领先条款之一。被称为局部完全活性空间组态相互作用（L-CASCI）的方法表示具有由感兴趣中心的局部轨道组成的活性空间的多参考计算。通过连续置换的活性空间，包括本地化的轨道对应于一个特定的中心的复杂的，所有的现场参数可以很容易地获得在一个高层次的理论与相应的低计算成本。对合成配合物的基准计算证实了该方法的有效性。作为一个例子的L-CASCI方法的大系统的适用性，我们确定的Mn（III）离子的四核锰簇的光系统II在其S2状态的两种结构形式的局部各向异性。
The interpretation of electron paramagnetic resonance spectra of polynuclear transition metal complexes in terms of individual contributions from each paramagnetic center can be greatly facilitated by the availability of theoretical methods that enable the reliable prediction of local spectroscopic parameters. In this work we report an approach that enables the application of multireference ab initio methods for the calculation of local zero field splitting tensors, one of the leading terms in the spin Hamiltonian for exchange-coupled systems of high nuclearity. The method referred to as local complete active space configuration interaction (L-CASCI) represents a multireference calculation with an active space composed of local orbitals of the center of interest. By successive permutation of the active space to include the localized orbitals corresponding to a particular center of the complex, all on-site parameters can be easily obtained at a high-level of theory with a corresponding low computational cost. Benchmark calculations on synthetic complexes confirm the validity of the approach. As an example of the applicability of the L-CASCI method to large systems, we determine the local anisotropy of the Mn(III) ion of the tetranuclear manganese cluster of photosystem II in both structural forms of its S2 state.