International Journal of Quantum Chemistry
Copyright © 2014 Wiley Periodicals, Inc., A Wiley Company
Online ISSN: 1097-461X
Associated Title(s): Journal of Computational Chemistry
Recently Published Articles
- Density functional study of hydrogen adsorption and diffusion on Ni-loaded graphene and graphene oxide
Qingzheng Li, Houyuan Wang, Haiping Xia, Shihao Wei and Jianhui Yang
Article first published online: 14 APR 2014 | DOI: 10.1002/qua.24680
First principles calculations indicate that hydrogen diffusion on the Ni/graphene interface is difficult due to the stronger NiH bond strength. Furthermore, the chemisorbed H atoms are unlikely to diffuse freely on the graphene surface. On the graphene oxide surface, both hydroxyl and epoxide groups do not facilitate hydrogen diffusion. Instead, they are readily attracted by the nearby Ni catalyst and react with water molecules.
- Substitution effect on the intermolecular halogen and hydrogen bonds of the σ-bonded fluorinated pyridine···XY/HX complexes (XY = F2, Cl2, ClF; HX = HF, HCl)
Vladimir Sladek, Kraiwan Punyain, Michal Ilčin and Vladimír Lukeš
Article first published online: 14 APR 2014 | DOI: 10.1002/qua.24679
The varying substitution on the pyridine ring affects the structure of the complexes. Intramolecular and intermolecular vibrational modes might serve for possible experimental identification of the complexes. The possible spontaneous formation at different temperatures is also affected by the substitution as well as on the interaction type between the two molecules. It is shown that some complexes may exist at 200°K, which is a common temperature in the upper troposphere.
- Density functional theory study of p-chloroaniline adsorption on Pd surfaces and clusters
Xiaobo He, Jinghui Lyu, Hu Zhou, Guilin Zhuang, Xing Zhong, Jian-Guo Wang and Xiaonian Li
Article first published online: 14 APR 2014 | DOI: 10.1002/qua.24681
p-chloroaniline, one important industrial intermediates for a variety of specific and fine chemicals, can be obtained by hydrogenation of chloronitrobenzene on Pd catalysts. Density functional theory calculations allow to identify a trend in the adsorption energies of p-chloroaniline on different Pd catalytic surfaces: cluster > stepped surfaces > flat surface.
- Load balancing by work stealing in quantum chemistry calculations. Application to hybrid density functional methods
Astrid Nikodem, Alexei V. Matveev, Thomas M. Soini and Notker Rösch
Article first published online: 3 APR 2014 | DOI: 10.1002/qua.24677
Parallel implementations of quantum chemistry programs targeting supercomputers are challenging applications of dynamic load balancing algorithms. An implementation of work stealing (WS) algorithms is discussed and compared to a static backend (ST) for up to 2048 cores. For the evaluation of four-center integrals advantages of task presorting based on a cost estimate (CS) are demonstrated for some systems. The WS implementation is applicable to various numerical algorithms appearing in a quantum chemistry package.
- Quantum monte carlo for activated reactions at solid surfaces: Time well spent on stretched bonds
Philip E. Hoggan and Ahmed Bouferguène
Article first published online: 3 APR 2014 | DOI: 10.1002/qua.24676
Quantum Monte Carlo (QMC) methods are used to show that stretched N2 is significantly under-bound in Density functional estimates. The deficit compared to QMC energies is used to locate a bond-length that behaves like the dissociation transition state. This geometry is adsorbed on Cu(111) and a QMC simulation of the combined system gives an indication of the dissociation barrier and its lowering compared to the gas phase. N radicals are the product of both channels.