用于大活性空间精确处理的多体展开CASSCF方法
MBE-CASSCF Approach for the Accurate Treatment of Large Active Spaces
AI总结：
本文提出MBE-CASSCF方法，将多体展开FCI与CASSCF结合，通过混合一阶轨道优化实现大活性空间的高效高精度计算，并成功应用于铁(II)卟啉的50电子50轨道自旋能隙研究。
摘要：
我们提出了一种新的完全活性空间自洽场（CASSCF）方法实现，该方法利用多体展开全组态相互作用（MBE-FCI）方法在大活性空间内增量近似电子结构。基于同时采用Super-CI和拟牛顿策略的混合一阶算法来优化分子轨道，我们证明了所得到的MBE-CASSCF方法具有计算高效性和高精度。我们在一组既定的数值测试上评估了该实现的性能，然后将MBE-CASSCF应用于研究铁(II)卟啉的三重态-五重态自旋能隙，活性空间大至50个电子在50个轨道中。
英文摘要：
We present a novel implementation of the complete active space self-consistent field (CASSCF) method that makes use of the many-body expanded full configuration interaction (MBE-FCI) method to incrementally approximate electronic structures within large active spaces. On the basis of a hybrid first-order algorithm employing both Super-CI and quasi-Newton strategies for the optimization of molecular orbitals, we demonstrate both computational efficacy and high accuracy of the resulting MBE-CASSCF method. We assess the performance of our implementation on a set of established numerical tests before applying MBE-CASSCF in the investigation of the triplet-quintet spin gap of iron(II) porphyrin with active spaces as large as 50 electrons in 50 orbitals.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
