The hybrid anti-symmetrized coupled channels method (haCC) for the tRecX code

We present a new implementation of the hybrid antisymmetrized Coupled Channels (haCC) method in the framework of the tRecX (Scrinzi, 2022 [6]). The method represents atomic and molecular multi-electron functions by combining CI functions, Gaussian molecular orbitals, and a numerical single-electron basis. It is suitable for describing high harmonic generation and the strong-field dynamics of ionization. Fully differential photoemission spectra are computed by the tSurff method. The theoretical background of haCC is outlined and key improvements compared to its original formulation are highlighted. We discuss control of over-completeness resulting from the joint use of the numerical basis and Gaussian molecular orbitals by pseudo-inverses based on the Woodbury formula. Further new features of this tRecX release are the iSurff method, new input features, and the AMOS gateway interface. The mapping of haCC into the tRecX framework for solving the time-dependent Schrödinger equation is shown. Use, performance, and accuracy of haCC are discussed on the examples of high-harmonic generation and strong-field photo-emission by short laser pulses impinging on the Helium atom and on the linear molecules N_2 and CO.

本研究在tRecX框架（Scrinzi，2022年文献[6]）中，提出了混合反对称耦合通道（hybrid antisymmetrized Coupled Channels，haCC）方法的全新实现版本。该方法通过结合组态相互作用（Configuration Interaction, CI）函数、高斯型分子轨道与数值单电子基组，构建原子与分子的多电子函数。其适用于高次谐波产生与电离强场动力学的理论描述。利用tSurff方法可计算全微分光电子能谱。本文概述了haCC方法的理论背景，并重点阐明了其相较于原始形式的关键改进之处。针对数值基组与高斯型分子轨道联合使用所引发的过度完备性问题，本文探讨了基于伍德伯里公式（Woodbury formula）的伪逆矩阵解决方案。本次tRecX版本更新的新增功能还包括iSurff方法、全新输入特性以及AMOS网关接口。本文展示了如何将haCC方法映射至用于求解含时薛定谔方程（time-dependent Schrödinger equation）的tRecX框架中。本文以氦原子、线性分子N₂与CO受短激光脉冲作用后的高次谐波产生及强场光发射过程为实例，探讨了haCC方法的使用方式、计算性能与预测精度。