Fukui matrices considered as the generalization of the concept of Fukui densities are decomposed into their pairing and unpairing contributions within the theory of the reduced density matrices. Their algebraic structure ...

The energy of a physical domain within a molecular system considered as a quantum open system is analyzed as a functional of the electron distribution dependence with the number of particles. Our attention is focused upon ...

This work describes the derivation of simple relationships between the density matrix of effectively unpaired electrons and the spin-density matrix in N-electron systems. The link between both devices turns out to be the ...

This report constitutes an application of our previous theoretical works on partitionings of the first-order reduced density matrix according to the atomic domains defined in the theory of atoms in molecules. The numerical ...

The knowledge of the properties and the applicability of domain-restricted matrices has provided important advances in the description of molecular electronic distributions. In this work, we perform a critical comparison ...

This Letter describes a partitioning of the expectation value 〈 over(S, ^) 2 〉 of an N-electron system (molecule, ion, radical, etc.) into one- and two-center contributions. The proposal is valid for both independent and ...

This work implements a variational determination of the elements of two-electron reduced density matrices corresponding to the ground and excited states of N-electron interacting systems based on the dispersion operator ...

This paper reports the derivation of a relationship between some elements of the cumulant matrix of the second-order reduced density matrix and the elements of the spin-density matrix. This relationship turns out to be ...

Grand-canonical like descriptions of many electron atomic and molecular open systems which are characterized by a non-integer number of electrons are presented. Their associated reduced density matrices (RDMs) are obtained ...