Effects of methods and basis set on ab initio calculations of electronic transport through hydrogenated Pt nanocontacts

摘要

The effects of varying methods and basis set on ab initio calculations of electronic transport through hydrogenated Pt nanocontacts have been investigated. The nanocontact atomic arrangement was simulated by means of two pyramids facing each other along the (001) direction, and containing either 5 or 14 atoms each. A hydrogen molecule was placed between the two pyramid apexes, transversal to the nanocontact axis. The reliability of various methods-basis set combinations has been checked by comparing with experimental data for the equilibrium distance and the vibrational frequency of PtH molecule. The study was carried out using a large set of methods including the most classic in the field of Quantum Chemistry (HF), density functional methods (HFLYP, BLYP, PW91PW91, TPSS) as well as hybrids (B3LYP). The most important outcome of this work is a call of attention to those using Quantum Chemistry methods to calculate the conductance through nanosystems, remarking on the need of an appropriate choice of the tools being used in a particular case. (c) 2008 Wiley Periodicals, Inc.