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

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

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.

Controlling Radical Formation in the Photoactive Yellow Protein Chromophore

To understand how photoactive proteins function, it is necessary to understand the photoresponse of the chromophore. Photoactive yellow protein (PYP) is a prototypical signaling protein. Blue light triggers trans–cis isomerization of the chromophore covalently bound within PYP as the first step in a photocycle that results in the host bacterium moving away from potentially harmful light. At higher energies, photoabsorption has the potential to create radicals and free electrons; however, this process is largely unexplored. Here, we use photoelectron spectroscopy and quantum chemistry calculations to show that the molecular structure and conformation of the isolated PYP chromophore can be exploited to control the competition between trans–cis isomerization and radical formation. We also find evidence to suggest that one of the roles of the protein is to impede radical formation in PYP by preventing torsional motion in the electronic ground state of the chromophore

Excited state dynamics of Photoactive Yellow Protein chromophores elucidated by high-resolution spectroscopy and ab initio calculations

We report on experimental high-resolution spectroscopic studies in combination with advanced theoretical calculations that focus on the excited-state dynamics of various forms of the chromophore of the Photoactive Yellow Protein (PYP), and the dependence of these dynamics on conformational and isosteric structure, as well as the biological environment. Three-colour nanosecond multiphoton ionization pump-probe studies confirm and extend previous conclusions that the dominant decay channel of the lowest excited pi pi* state (the so-called V' state) of methyl-4-hydroxycinnamate is picosecond internal conversion to the adiabatically lower n pi* state, and enable us to resolve apparent contradictions with picosecond pump-probe studies. Comparison of multiphoton ionization and laser induced fluorescence excitation spectra leads to the assignment of the hitherto elusive excitation spectrum of the V(pp*) state. Complexation of methyl-4-hydroxycinnamate with water radically changes the excited-state dynamics; internal conversion to the np* state is absent, and bond isomerization channels instead play a prominent role. Excited states of the thio-ester compound, the form in which the chromophore is present in PYP, have till the present study remained out of reach of gas-phase studies. The excitation spectra obtained here show a broad, almost structureless band system, giving evidence for enhanced nonradiative decay channels. The gas-phase results will be discussed in the context of results from ultrafast studies on these two chromophores in solution