although extensive experimental work has been carried out during the last several years, experimental reaction rate constants are available only for hundreds of compounds. therefore, it is useful to develop a theoretical prediction method, which can be used to obtain estimates of the necessary kinetic parameters. one of the most successful approaches to predict chemical properties starting only...

in this paper, the structural properties of the b30n20 molecule have been investigated at b3lyp/6-31g (d) level of theory. the optimized structure and electronic properties calculations for the studiedmolecule have been performed using gaussian 03 program. a mathematical equation of third degreewas exploited for the correlation and exchange energy with the number of primitives. the naturalbondi...

The azide-alkyne cycloaddition assisted by a self-assembled molecular flask developed by Rebek and coworkers (Org. Lett., 2002, 4, 327) has been simulated by means of the ONIOM methodology, thereby evidencing the reliability of this theoretical approach to model such large encapsulated systems. Experimental evidences accounting for this transformation within the supramolecular assembly such as ...

Métodos compostos adaptados ao método ONIOM foram utilizados no cálculo teórico de afinidades por próton (PA) e eletrônica (EA) para um grupo de 50 moléculas (álcoois, cetonas, radicais e alcenos). A energia eletrônica foi descrita considerando-se o escalonamento de ZPE (λ) e a correção de alto nível (HLC). O valor ótimo para λ foi obtido através dos dados de PA. Os cálculos de EA foram utiliza...

A DFT algorithm, the Extended Subband DFT (ESB−−DFT), is presented, which aims to overcome the problem of low accuracy the Subband DFT (SB−−DFT) algorithm suffers from, when applied in its approximate mode for signals with full spectrum. The proposed ESB−DFT is based upon the analysis of the input signal using a Filter Bank (FB) and the computation of its DFT from the lower length DFTs that cor...

???????i? ??i??i??????? ?? ??i???i????? ???? ???i?? ? ?????????? ???? ????i????? ???????? ?????i?????? ???????????i? ???????? ?i?i????? ???????????. ??????i?? i???????????? ?i?????? ??? ?????i ?????????i????? ?????????? (IEF-PCM) ?????????? ?????? ?????????? ???????????????? ?? ?i??i ????i? B3LYP/6-311++G(d,p). ??????i ??’???? ?i? ????????? ????????? ????i? ? ????????? (AIM) i ????????????? ???...

The ozonization at the vacancy defect site of the single-walled carbon nanotube has been studied by static quantum mechanics and atom-centered density matrix propagation based ab initio molecular dynamics within a two-layered ONIOM approach. Among five different reaction pathways at the vacancy defect, the reaction involving the unsaturated active carbon atom is the most probable pathway, where...