T3NS: Three-Legged Tree Tensor Network States

kgunst — Thu, 15 Mar 2018 09:07:08 +0000

K. Gunst, F. Verstraete, S. Wouters, Ö. Legeza, D. Van Neck

Journal of Chemical Theory and Computation

14 (4), pp 2026–2033

2018

Abstract

We present a new variational tree tensor network state (TTNS) ansatz, the three-legged tree tensor network state (T3NS). Physical tensors are interspersed with branching tensors. Physical tensors have one physical index and at most two virtual indices, as in the matrix product state (MPS) ansatz of the density matrix renormalization group (DMRG). Branching tensors have no physical index, but up to three virtual indices. In this way, advantages of DMRG, in particular a low computational cost and a simple implementation of symmetries, are combined with advantages of TTNS, namely incorporating more entanglement. Our code is capable of simulating quantum chemical Hamiltonians, and we present several proof-of-principle calculations on LiF, N$_2$, and the bis(μ-oxo) and μ–η$^2$:η$^2$ peroxo isomers of [Cu$_2$O$_2$]$^{2+}$.

DOI

http://dx.doi.org/10.1021/acs.jctc.8b00098

Tree tensor networks in ab initio quantum chemistry

kgunst — Wed, 07 Mar 2018 08:41:19 +0000

K. Gunst, F. Verstraete, S. Wouters, Ö. Legeza, D. Van Neck

ISBN/ISSN:

Poster

Conference / event / venue

Numerical Methods in Strongly Correlated Quantum Systems

Marburg, Germany

Monday, 19 February, 2018 to Friday, 23 February, 2018

Center for Molecular Modeling - Ö. Legeza

T3NS: Three-Legged Tree Tensor Network States

Abstract

DOI

Tree tensor networks in ab initio quantum chemistry

Conference / event / venue