Descifrado de Cesar por Medio de Análisis de Frecuencia para Tres Idiomas

En este trabajo se cifrar por medio del algoritmo de Cesar y se descifrar por fuerza bruta, mediante un análisis de frecuencias, se introduce el análisis de frecuencia para 3 idiomas para que el criptograma, se pueda descifrar en estos 3 idiomas elegidos, los textos llanos pueden estar en español, inglés, y portugués, la interfaz contará con tres secciones (texto plano, texto cifrado y texto descifrado), un área de salida de datos tipo consola y un área de comandos. Estos deben permitir las acciones de cargar texto desde un archivo, limpiar los campos, realizar el cifrado y descifrado, seleccionar un idioma de trabajo y realizar el ataque por análisis de frecuencias. Ya que el análisis de frecuencia varía dependiendo del idioma que utilicemos

Cooperative and anticooperative effects in resonance assisted hydrogen bonds in merged structures of malondialdehyde

We analyzed non-additive effects in resonance assisted hydrogen bonds (RAHBs) in different b-enolones, which are archetypal compounds of these types of interactions. For this purpose, we used (i) potential energy curves to compute the formation energy, DERAHB form , of the RAHBs of interest in different circumstances along with (ii) tools offered by quantum chemical topology, namely, the Quantum Theory of Atoms In Molecules (QTAIM) and the Interacting Quantum Atoms (IQA) electronic energy partition. We established the effect that a given H-bond exerts over DERAHB form associated with another RAHB, determining in this way the cooperativity or the anticooperativity of these interactions. The mesomeric structures and the QTAIM delocalisation indices are consistent with the determined cooperative or anticooperative character of two given RAHBs. The HB cooperativity and anticooperativity studied herein are directly reflected in the IQA interaction energy EOH int , but they are modulated by the surrounding hydrocarbon chain. The IQA decomposition of DEcoop, a measure of the cooperativity between a pair of interacting RAHBs, indicates that the analyzed H-bond cooperative/anticooperative effects are associated with greater/smaller (i) strengthening of the pseudo-bicyclic structure of the compounds of interest and (ii) electron localisations with its corresponding changes in the intra and intermolecular exchange–correlation contributions to DERAHB form . Overall, we expect that this investigation will provide valuable insights into the interplay among hydrogen bonded atoms and the p system in RAHBs contributing in this way to the understanding of the general features of H-bonds.

Atoms in molecules in real space: a fertile field for chemical bonding

In this perspective, we review some recent advances in the concept of atoms-in-molecules from a real space perspective. We first introduce the general formalism of atomic weight factors that allows unifying the treatment of fuzzy and non-fuzzy decompositions under a common algebraic umbrella. We then show how the use of reduced density matrices and their cumulants allows partitioning any quantum mechanical observable into atomic or group contributions. This circumstance provides access to electron counting as well as energy partitioning, on the same footing. We focus on how the fluctuations of atomic populations, as measured by the statistical cumulants of the electron distribution functions, are related to general multi-center bonding descriptors. Then we turn our attention to the interacting quantum atom energy partitioning, which is briefly reviewed since several general accounts on it have already appeared in the literature. More attention is paid to recent applications to large systems. Finally, we consider how a common formalism to extract electron counts and energies can be used to establish an algebraic justification for the extensively used bond order-bond energy relationships. We also briefly review a path to recover one-electron functions from real space partitions. Although most of the applications considered will be restricted to real space atoms taken from the quantum theory of atoms in molecules, arguably the most successful of all the atomic partitions devised so far, all the take-home messages from this perspective are generalizable to any real space decompositionsWe acknowledge the spanish MICINN, grant PID2021-122763NB-I00 and the FICyT, grant IDI/2021/000054 for financial support. TRR gratefully acknowledges DGTIC/UNAM for computer time (LANCAD-UNAM-DGTIC 250

A theoretical study of singlet low-energy excited states of the benzene dimer

The singlet ground and low-energy excited states of the benzene dimer in D6h geometry are characterized using second order multireference perturbation theory (CASPT2). The counterpoise-corrected spectroscopic parameters of the benzene excimer are in quantitative agreement with experiment. The same method was used to compute a submanifold of the potential energy hypersurface of the first excited state of the benzene dimer, exhibiting two local minima in addition to a saddle point between them. This study demonstrates the suitability of CASPT2 to describe the benzene excimer and suggests that the method can be used to describe weak intermolecular interactions involving excited states. © 2006 Elsevier B.V. All rights reserved