Physics

Renormalization

Mathematics

Symmetric matrix

Renormalization group

Propagator

Statistical physics

Mathematical optimization

Hamiltonian (control theory)

Eigenvalues and eigenvectors

Chemistry

State-transition matrix

Molecular physics

Spectral line

Density matrix

Quantum mechanics

Density matrix renormalization group

Quantum

Journal of Chemical Theory and Computation

We implement and apply time-dependent density matrix renormalization group (TD-DMRG) algorithms at zero and finite temperature to compute the linear absorption and fluorescence spectra of molecular aggregates. Our implementation is within a matrix product state/operator framework with an explicit treatment of the excitonic and vibrational degrees of freedom, and it uses the locality of the Hamiltonian in the zero-exciton space to improve the efficiency and accuracy of the calculations. We demonstrate the power of the method by calculations on several molecular aggregate models, comparing our results against those from multilayer multiconfiguration time-dependent Hartree and n-particle approximations. We find that TD-DMRG provides an accurate and efficient route to calculate the spectrum of molecular aggregates.

Time-Dependent Density Matrix Renormalization Group Algorithms for Nearly Exact Absorption and Fluorescence Spectra of Molecular Aggregates at Both Zero and Finite Temperature