The conformational analysis of ethylene-norbornene chains (E-N) has been carried out using AM1, MM2, AMBER and OPLS methods taking into consideration the possibility of binding the ethylene monomers to norbornene monomers at various positions, i.e. exo-exo, exo-endo, endo-endo. The chain that is formed by connecting exo-endo positions of the monomers has lower torsional barrier energy than thos...

Rapid yet accurate pKa prediction for druglike molecules is a key challenge in computational chemistry. This study uses PM6-DH+/COSMO, PM6/COSMO, PM7/COSMO, PM3/COSMO, AM1/COSMO, PM3/SMD, AM1/SMD, and DFTB3/SMD to predict the pKa values of 53 amine groups in 48 druglike compounds. The approach uses an isodesmic reaction where the pKa value is computed relative to a chemically related reference ...

Infrared (IR) and ultraviolet (UV) spectroscopic analysis of eight structural isomers of C20 carbon nanostructures, i.e. ring, tadpole, bow-tie, dumb-bell, spiro, propellane, bowl and cage, were performed at different levels of theory including semi-empirical (AM1 and PM3), Hartree-Fock (HF/6-31++G, 6-31++G**) and density functional theory (B3LYP/6-31++G, 6-31++G**). A broad range of IR spectra...

There are many claims that quantum mechanics plays a key role in the origin and/or operation of biological organisms. The mechanism of the meiosis, mitosis and gametes life cycle from the view-point of quantum for human has been represented. The quantum gates have been used to simulate these processes for the first time. The reason of several hundred sperms has been explained in the male too

Title of Document: QUANTUM MECHANICS AND QUANTUM INFORMATION THEORY Wesley William Van Camp, Doctor of Philosophy, 2009 Directed By: Distinguished University Professor and Chair of the Committee for Philosophy and the Sciences, Jeffrey Bub, Department of Philosophy The principle aim of this dissertation is to investigate the philosophical application of quantum information theory to interpretat...

We discuss the derivation of the so-called semi-classical equations for both mini-superspace and dilaton gravity. We find that there is no systematic derivation of a semi-classical theory in which quantum mechanics is formulated in a space-time that is a solution of Einstein's equation, with the expectation value of the matter stress tensor on the right-hand side. The issues involved are relate...

Human beings use different methods to understand the world, religiously or scientifically, empirically or theoretically, synthetically or analytically. Quantum chemistry is one of the these methods. Starting from first principles of quantum mechanics, applying different mathematical and physical approximations, the behaviors of molecules are described. Before the discussion of the complex theor...

The rational design of molecularly imprinted polymers (MIPs) has been a major contributor to their reputation as "plastic antibodies" - high affinity robust synthetic receptors which can be optimally designed, and produced for a much reduced cost than their biological equivalents. Computational design has become a routine procedure in the production of MIPs, and has led to major advances in fun...

The sequential QM/MM methodology is used to describe the solvent effects on the electronic absorption spectra of organic molecules in solution. The structure of the liquid is generated by Monte Carlo computer simulation. Configurations composed by the solute and several solvent molecules are selected for a posteriori quantum mechanical calculations of the spectra. Situations are considered wher...

We review electronic structure calculations of finite-length semiconducting carbon nanotubes using time-dependent density functional theory (TD-DFT) and the time dependent Hartree-Fock (TD-HF) approach coupled with semi-empirical AM1 and ZINDO Hamiltonians. We specifically focus on the energy splitting, relative ordering, and localization properties of optically active (bright) and optically fo...