论文标题
从任意参考子空间中接近完整的配置相互作用低能频谱
Approaching the Full Configuration Interaction Low-Energy Spectrum from an Arbitrary Reference Subspace
论文作者
论文摘要
在先前的工作（ARXIV：2010.02027）中，我们展示了如何通过梯度下降或Quasi-Newton算法来作为任意参考波函数的函数获得完整的构型相互作用（FCI）基态能量。在这里，我们扩展了这种方法，并考虑了从任意参考子空间中对哈密顿量低能体空间的优化。沿着优化路径的能量是根据参考子空间中各州之间的过渡矩阵元素获得的。我们展示了该算法的应用，该算法与由非正交构型相互作用（NOCI）形式主义构建的参考子空间描述了甲醛的避免在LIF中避免的穿越，而甲醛的低层单元和三胞胎光谱。
In a previous work (arXiv:2010.02027) we showed how the full configuration interaction (FCI) ground state energy can be obtained as a functional of an arbitrary reference wavefunction by means of a gradient descent or quasi-Newton algorithm. Here, we extend this approach and consider the optimization of the low-energy subspace of the Hamiltonian from an arbitrary reference subspace. The energies along the optimization path are obtained in terms of transition matrix elements among the states in the reference subspace. We show an application of the algorithm with a reference subspace constructed from a non-orthogonal configuration interaction (NOCI) formalism to describe the avoided crossing in LiF and the low-lying singlet and triplet spectrum of formaldehyde.
