Pyrazine derivatives are important class of compounds with diverse biological and cytotoxic activities and clinical applications. In this study, B3 p 86 / 6 – 31 + + G * was used to compute and map the molecular surface electrostatic potentials of a group of substituted amides of pyrazine-2-carboxylic acids to identify common features related to their subsequent cytotoxicities. Several statisti...

a quantum chemical investigation was carried out to study the properties of intermolecular f•••f, br•••br and br•••o interactions in crystalline 1-bromo-2,3,5,6-tetrafluoro-nitrobenzene (bfnb). this system was selected to mimic the halogen-halogen as well as halogen bonding interactions found within crystal structures as well as within biological systems. we found that fluorine atoms have weak ...

influence of aluminum, gallium, indium- doping on the boron-nitride nanotubes (bnnts) investigated with density functional theory (dft) and hartreefock (hf) methods. for this purpose, the chemical shift of difference atomic nucleus was studied using the gauge included atomic orbital (giao) approch. in the following, structural parameter values, electrostatic potential, thermodynamic parameters,...

In this study, we theoretically investigated Methyl hydrazinecarbodithioate by quantum chemical calculations for geometry optimization, vibration frequencies, and electronic structure parameters. The geometry optimization by DFT, ab initio MP2 method and the frequency calculation by DFT method was performed at the highest available Pople style 6-311G++(3df,3pd) basis set level. The semi-emp...

the importance of constructing the appropriate green function to solve a wide range of problems inelectromagnetics and partial differential equations is well-recognized by those dealing with classical electrodynamics and related fields. although the subject of obtaining the green function for certain geometries has been extensively studied and addressed in numerous sources, in this paper a syst...

In this work, by using density functional theory, the adsorption of Nitramide (NH2NO2) molecule on the surface of pristine, B, As and B&As doped (4,4) armchair aluminum nitride nanotube (AlNNTs) is investigated. From optimized structures the adsorption energy, deformation energy, natural bond orbital (NBO), atom in molecule (AIM), quantum parameters, reduced density gradient (RDG) and molecular...

electrostatic potential as well as the local volume charge density are computed for a macromolecule by solving the poisson-boltzmann equation (pbe) using the finite element method (fem). as a verification, our numerical results for a one dimensional pbe, which corresponds to an infinite-length macromolecule, are compared with the existing analytical solution and good agreement is found. as a ma...

This paper introduces a self-consistent computational protocol for modeling protein electrostatic potentials according to static point-charge model distributions. The protocol involves a simple space-domain decomposition scheme where individual molecular domains are modeled as Quantum-Mechanical (QM) layers embedded in the otherwise classical Molecular-Mechanics (MM) protein environment. Electr...