Reliability of soft-core approximations in theoretical studies of molecules in intense laser fields
Reliability of soft-core approximations in theoretical studies of molecules in intense laser fields
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强激光场分子理论研究中软核近似的可靠性
DOI：
10.1103/physreva.81.023414
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发表时间：
2010
影响因子：
2.9
通讯作者：
J. Rost
中科院分区：
文献类型：
--
作者：
Alexander Kästner;F. Grossmann;R. Schmidt;J. Rost
在降维模型中，常用的软化库仑奇异性的方法会导致与精确势的数值结果不可控的差异。即使是对齐几何形状的简单氢分子离子的电离和解离概率以及高次谐波产生光谱也证明了这一点。软核模型在全维中表现得更好，从而失去了它们的一个优势，即通过降低维度来获得的计算时间增益。然而，软核势的简单得多的数值实现延续到全维。此外，本文还推广了[M. Lein，P. P. Corso，J. P. Marangos，and P. L. Knight，Phys.Rev.A67，023819（2003）]，导致了对精确结果的巨大改进，这对于未来没有圆柱对称的计算非常有希望。
The popular approach of softening the Coulomb singularity in models with reduced dimensionality leads to uncontrollable discrepancies with numerical results obtained using exact potentials. This is demonstrated for ionization and dissociation probabilities as well as for high-order harmonic generation spectra even of the simple hydrogen molecular ion in aligned geometry. Soft-core models perform better in full dimensions, thereby losing one of their advantages, namely the gain in computation time that is achieved by going to reduced dimensionality. However, the much simpler numerical implementation of soft-core potentials carries over to full dimensions. Moreover, a generalization of the soft-core potential given in previous work [M. Lein, P. P. Corso, J. P. Marangos, and P. L. Knight, Phys. Rev. A 67, 023819 (2003)] is proposed, leading to a tremendous improvement toward the exact results, which is very promising for future calculations without cylindrical symmetry.