2021/09/08 by Chérif F. Matta, Cherif F. Matta, Matta, Cherif F. +2
Biochemistry, Genetics and Molecular Biology · Chemistry · Materials Science · Physics and Astronomy · #Biomolecules (q-bio.BM) #Crystal Structures and Properties #FOS: Biological sciences #FOS: Physical sciences #Molecular spectroscopy and chirality #Quantum Physics (quant-ph) #X-ray Diffraction in Crystallography #q-bio.BM #quant-ph
paper · pdf · doi:10.48550/arxiv.2109.03388
arxiv created 2021/09/08 · openalex publication_date 2021/09/08 · arxiv updated 2021/09/09 · openalex created_date 2021/09/13 · openalex updated_date 2026/07/28
Consider a projector matrix P, representing the first order reduced density matrix in a basis of orthonormal atom-centric basis functions. A mathematical question arises, and that is, how to break P into its natural component kernel projector matrices, while preserving N-representability of P. The answer relies upon 2- projector triple products, P'jPP'j. The triple product solutions, applicable within the quantum crystallography of large molecules, are determined by a new form of the Clinton equations, which - in their original form - have long been used to ensure N-representability of density matrices consistent with X-ray diffraction scattering factors.