Journal of the Mexican Chemical Society
Print version ISSN 1870-249X
FLORES-GALLEGOS, Nelson and ESQUIVEL, Rodolfo O.. von Neumann Entropies Analysis in Hilbert Space for the Dissociation Processes of Homonuclear and Heteronuclear Diatomic Molecules. J. Mex. Chem. Soc [online]. 2008, vol.52, n.1, pp. 19-30. ISSN 1870-249X.
Quantum Information Theory is a new field with potential implications for the conceptual foundations of Quantum Mechanics through density matrices. In particular, information entropies in Hilbert space representation are highly advantageous in contrast with the ones in phase space representation since they can be easily calculated for large systems. In this work, novel von Neumann conditional, mutual, and joint entropies are employed to analyze the dissociation process of small molecules, Cl2 and HCl, by using the spectral decomposition of the first reduced density matrix in natural atomic orbital-based representation which allows us to assure rotational invariance, N- and v-representability in the Atoms-in-Molecules (AIM) scheme. Quantum information entropies permit to analyze the dissociation process through quantum mechanics concepts such as electron correlation and entanglement, showing interesting critical points which are not present in the energy profile, such as charge depletion and accumulation, along with bond breaking regions.
Keywords : Quantum Information Theory; entanglement; diatomic molecules; Ab initio calculations.