in this work, the optimization calculations were carried out on quetiapine hemifumarat, 4, and its analogues, 1-5. these calculations were carried out using the b3lyp/6-31g(d) level of theory. the dft calculations clarified a boat structure for dibenzothiazepine moiety of the molecule which piperazine moiety has a chair conformation. thermal energies (e), enthalpies (h), and free energies (g) o...

in this work the performance of a wavelength division multiple access (wdma) system with direct detection receiver is investigated. for this purpose, the probability of error in a wdma network with ook modulation considering crosstalk, isi, photo detector noise and thermal noise is calculated and the effect of each on system performance is investigated. the system performance in presence of pin...

in this paper, the structure of a new 16-membered macrocyclic schiff base compound n,n′-(3,3′-dimethoxy-2,2′-(propane-1,3-diyldioxy)dibenzylidene)propane-1,3-diamine, c22h26n2o4 (1), derived from 1,3-propanediamine and 3,3′-dimethoxy-2,2′-(propane-1,3-diyldioxy)dibenzaldehyde has been studied by single crystal x-ray diffraction, dft calculations at b3lyp/6-31g** and ft-ir spectroscopy. the titl...

ab initio calculations at hf/6-31g* level of theory for geometry optimization and mp2/6-31g*//hf/6-31g* for a single point total energy calculation are reported for the importantenergy-minimum conformations and transition-state geometries of 1, 3-diazacyclohepta-1, 2-diene (2) and 1, 3-diazacycloocta-1, 2-diene (3). the c2 symmetric twist-chair (2-tc)conformation of 2 is calculated to be 7.4 kj...

A short introduction to periodic bandstructure methods suitable for the calculation of Mössbauer parameters is presented. These methods are based on density functional theory (because we want to treat big and complicated systems) and must be accurate not only in the bonding region (like pseudopotential approaches), but also near the atomic nuclei since Mössbauer parameters depend crucially on t...

population-based genetic association studies have proven to be a powerful tool in identifying genes implicated in many complex human diseases that have a huge impact on public health. an essential quality control step in such studies is to undertake hardy-weinberg equilibrium (hwe) calculations. deviations from hwe in the control group may reflect important problems including selection bias, po...

glycine, alanine and valine are taken as amino acids with an equal polar head and with thedifference in the length of hydrocarbon chains. the structural optimizations show the results of theisolated glycine, alanine and valine in the gases phase, at the hartree-fock level by means ofsto-3g,3-21g, 6-31g and 6-31+g basis sets. the calculations were performed for the ten (1-10)solvents using pcm m...