The interaction energies of free acetone molecules with surfaces of two different ice polymorphs have been investigated by quantum chemical methods. Special emphasis has been given to sites for adsorption on the (0001) surface of hexagonal ice (I(h)) and the (1[combining macron]01) surface of cubic ice (I(c)), respectively. The structural optimisations made use of conventional electronic struct...

Herein, the absorption maximum of bacteriorhodopsin (bR) is calculated using our recently developed method in which the whole protein can be treated quantum mechanically at the level of INDO/S-CIS//ONIOM (B3LYP/6-31G(d,p): AMBER). The full quantum mechanical calculation is shown to reproduce the so-called opsin shift of bR with an error of less than 0.04 eV. We also apply the same calculation f...

We present a hybrid ab initio molecular dynamics scheme that includes both DFT and HartreeFock based extended Lagrangian and converged post-Hartree-Fock Born-Oppenheimer components, combined within the framework of molecular fragmentation based electronic structure. The specific fragmentation algorithm used here is derived from ONIOM, but includes multiple, overlapping “model” systems. The inte...

A análise conformacional do dipeptídeo protonado ciclo-[(S)-fenilalanil-(S)-histidil], denominado ciclo-[(S)-Phe-(S)-His-H], dentro das cavidades de novos materiais porosos do tipo IRMOFs-phen (redes metal-orgânicas isoreticulares com pontes de 2,7-dicarboxilato fenantreno substituído) foi realizada com o método de química quântica AM1. Foram consideradas duas formas do ciclo-[(S)-Phe-(S)-His-H...

Decorating of Transition metals (TMs) on the "AlMg" nanoalloy has been studied basis Langmuir adsorption applying "ONIOM" model with three levels «high, medium and low» by using "LANL2DZ /6-31+G(d,p)/EPR-III", "semi-empirical" "MM2" functions. The fluctuation "NQR" estimated inhibiting role pyridine alkylpyridines containing 2-picoline (2Pic), 3-picoline (3Pic) ,4-picoline (4Pic), 2,4-lutidine ...

As the first application of our recently developed ONIOM2(QM:MM) and ONIOM3(QM:QM:MM) codes to the metalloenzymes with a large number of protein residues, two members of the non-heme protein family, methane monooxygenause and ribonucleotide reductase, have been chosen. The "active-site + four alpha-helical fragments" model was adopted which includes about 1000 atoms from 62 residues around the ...