Hybrid-Basis Close-Coupling Interface to Quantum Chemistry Packages for the Treatment of Ionization Problems
Hybrid-Basis Close-Coupling Interface to Quantum Chemistry Packages for the Treatment of Ionization Problems
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DOI：
10.1021/acs.jctc.6b00907
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发表时间：
2017-02-01
影响因子：
5.5
通讯作者：
Martin, Fernando
中科院分区：
文献类型：
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作者：
Marante, Carlos;Klinker, Markus;Martin, Fernando
阿秒泵浦探测实验中可观测量的理论描述需要对系统电离连续体有良好的表示。然而，对于多电子分子来说，由于相关电子波函数的短程结构复杂，这仍然是一个挑战。尽管量子化学包（QCP）实施复杂的方法来计算束缚电子分子态已经很成熟，但用于连续体的类似工具尚未广泛使用。为了解决这个问题，我们开发了一种新方法，通过混合高斯 B 样条基础，将现有 QCP 与紧耦合散射方法结合起来。为了说明这种方法的可行性，我们报告了氦原子和氢分子的多通道电离结果，这些结果与现有的准确基准非常一致。这些发现，加上 QCP 描述广泛化学系统的多功能性，表明这是研究多电子系统电离的有效方法，其中相关性和交换对称性起着主要作用。
The theoretical description of observables in attosecond pumpprobe experiments requires a good representation of the systems ionization continuum. For polyelectronic molecules, however, this is still a challenge, due to the complicated short-range structure of correlated electronic wave functions. Whereas quantum chemistry packages (QCP) implementing sophisticated methods to compute bound electronic molecular states are well-established, comparable tools for the continuum are not widely available yet. To tackle this problem, we have developed a new approach that, by means of a hybrid Gaussian-B-spline basis, interfaces existing QCPs with close-coupling scattering methods. To illustrate the viability of this approach, we report results for the multichannel ionization of the helium atom and of the hydrogen molecule that are in excellent agreement with existing accurate benchmarks. These findings, together with the versatility of QCPs to describe a broad range of chemical systems, indicate that this is a valid approach to study the ionization of polyelectronic systems in which correlation and exchange symmetry play a major role.