Necessary N-representability Constraints from Time-reversal Symmetry for Periodic Systems
Abstract
The variational calculation of the two-electron reduced density matrix (2-RDM) is extended to periodic molecular systems. If the 2-RDM theory is extended to the periodic case without consideration of time-reversal symmetry, however, it can yields energies that are significantly lower than the correct energies. We derive and implement linear constraints that enforce time-reversal symmetry on the 2-RDM without destroying its computationally favorable block-diagonal structure from translational invariance. Time-reversal symmetry is distinct from space-group or spin (SU(2)) symmetries which can be expressed by unitary transformations. The time-reversal symmetry constraints are demonstrated through calculations of the metallic hydrogen chain and the one-dimensional lithium hydride crystal.
Keywords
Cite
@article{arxiv.1606.06262,
title = {Necessary N-representability Constraints from Time-reversal Symmetry for Periodic Systems},
author = {Nicholas C. Rubin and David A. Mazziotti},
journal= {arXiv preprint arXiv:1606.06262},
year = {2016}
}