Determining the Ensemble <i>N</i>-Representability of Reduced Density Matrices.

ABSTRACT: The N-representability problem for reduced density matrices remains a fundamental challenge in electronic structure theory. Following our previous work that employs a unitary-evolution algorithm based on an adaptive derivative-assembled pseudo-Trotter variational quantum algorithm to probe pure-state N-representability of reduced density matrices [J. Chem. Theory Comput. 2024, 20, 9968], in this work we propose a practical framework for determining the ensemble N-representability of a p-body matrix. This is accomplished using a purification strategy that embeds an ensemble state into a pure state defined on an extended Hilbert space, such that the reduced density matrices of the purified state reproduce those of the original ensemble. By iteratively applying var

SUBMITTER: Ona OB 

PROVIDER: S-EPMC12805516 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature