Semi-empirical calculations including an empirical dispersive correction are used to calculate intermolecular interaction energies and structures for a large database containing 156 biologically relevant molecules (hydrogen-bonded DNA base pairs, interstrand base pairs, stacked base pairs and amino acid base pairs) for which MP2 and CCSD(T) complete basis set (CBS) limit estimates of the intera...

Indole-3-carbinol (I3C) is a plant compound derived from glucosinolates, found in cruciferous vegetables. Researchers have indicated that I3C shows great promise as a cancer preventative and hormone-balancing agent. HyperChem 7.5 software was used for quantum mechanical calculations. The geometry optimization was carried out using Ab Initio method. QSAR parameters were generated with semi empir...

Phosphate transfer reactions are ubiquitous in nature and play fundamental roles in ATP hydrolysis and protein phosphorylation processes. The mechanisms of these reactions involve a pentacoordinated phosphorus atom that can be an intermediate or a transition state. These structures are very sensitive to both internal and external electrostatic effects and their description with quantum mechanic...

The Methotrexate delivery by carbon nanotubes (CNTs) and the structural changes of drugcombination upon the carbon nanotubes and bio thermodynamic of the drug have been studied by molecularcomputational methods. Computational molecular methods have been fulfilled by molecular mechanics methods with four force field, and semi empirical with all methods. We investigate different param...

As a commonly used structure-based approach for virtual screening, molecular design and lead optimization, molecular docking can search the preferred orientation and conformation of a ligand for its optimal binding to a receptor or enzyme active site. In doing so, selecting an appropriate method to calculate the electrostatic potentials is critical. In the current report, nine different semi-em...

An improved kinetic model for the Meinel bands of OH has been constructed from rate constants and Einstein A coefficients derived in recent laboratory experiments. Using a semiempirical parameterization of the state-to-state rate constants for OH(v) quenching by O2, the absolute OH(v) nightglow radiances are modeled to within the accuracies of the atmospheric constituent concentrations and the ...

Gas phase and aqueous phase quantum chemical calculations for the inhibition efficiency of some substituted Benzothiazole (BTH) and its 2-methyl (MeBTH), 2-amino (ABTH), 2-mercapto (MBTH) and 2-phenyl (PhBTH) as corrosion inhibitors for brass in HClO4 were investigated by means of the AM1, PM6, MNDO and RM1 semi-empirical SCF molecular orbital methods. The calculated quantum chemical parameters...