Tree tensor network state study of the ionic-neutral curve crossing of LiF

Understand

We present a tree-tensor-network-state (TTNS) method study of the ionic-neutral curve crossing of LiF.

• For this ansatz, the long-range correlation deviates from the mean-field value polynomially with distance, thus for quantum chemical applications the computational cost could be significantly smaller than that of previous attempts using the density matrix renormalization group (DMRG) method.
• Optimization of the tensor network topology and localization of the avoided crossing are discussed in terms of entanglement.