Multilayer multiconfiguration time-dependent Hartree method: implementation and applications to a Henon-Heiles hamiltonian and to pyrazine.
Multilayer multiconfiguration time-dependent Hartree method: implementation and applications to a Henon-Heiles hamiltonian and to pyrazine.
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DOI：
10.1063/1.3535541
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发表时间：
2010-12
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通讯作者：
O. Vendrell;H. Meyer
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文献类型：
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作者：
O. Vendrell;H. Meyer
本文讨论了多层多组态时变Hartree(ML-MCTDH)方法，并基于Manthe[J.Chem]给出的递归ML-MCTDH算法给出了任意多层的完全通用实现。太棒了。128,164116(2008年)]。该方法首先应用于广义Henon-Heiles(HH)哈密顿量。对于6D HH，ML-MCTDH的开销使得该方法比MCTDH更慢，但对于18D HH，ML-MCTDH开始具有竞争性。我们还报告了使用七层方案对HH哈密顿量进行的1458D模拟。用Raab等人的24D哈密顿量计算了吡嗪的光吸收光谱。作者声明：[J.Chem.太棒了。110,936(1999)]为该方法提供了一个现实的分子测试案例。快速和小规模的ML-MCTDH计算只需要参考MCTDH计算的一小部分时间和资源，就可以提供具有所有正确特征的光谱。接受稍大的偏差，计算速度可以加快到只需要7分钟。当将该方法推向收敛时，得到的结果与现有的最好的基于4.6×10(7)个随时间变化系数的波包的MCTDH基准相似，而波函数更紧凑，仅由4.5×10(5)个系数组成，所需计算时间更短。
The multilayer multiconfiguration time-dependent Hartree (ML-MCTDH) method is discussed and a fully general implementation for any number of layers based on the recursive ML-MCTDH algorithm given by Manthe [J. Chem. Phys. 128, 164116 (2008)] is presented. The method is applied first to a generalized Henon-Heiles (HH) hamiltonian. For 6D HH the overhead of ML-MCTDH makes the method slower than MCTDH, but for 18D HH ML-MCTDH starts to be competitive. We report as well 1458D simulations of the HH hamiltonian using a seven-layer scheme. The photoabsorption spectrum of pyrazine computed with the 24D hamiltonian of Raab et al. [J. Chem. Phys. 110, 936 (1999)] provides a realistic molecular test case for the method. Quick and small ML-MCTDH calculations needing a fraction of the time and resources of reference MCTDH calculations provide already spectra with all the correct features. Accepting slightly larger deviations, the calculation can be accelerated to take only 7 min. When pushing the method toward convergence, results of similar quality than the best available MCTDH benchmark, which is based on a wavepacket with 4.6×10(7)time-dependent coefficients, are obtained with a much more compact wavefunction consisting of only 4.5×10(5) coefficients and requiring a shorter computation time.