In data 30 settembre 2011 alle ore 23:25:38, Alex Shearer <alex124678 at nc.rr.com> ha scritto: > The geometries of adsorption are often non-trivial; in papers dealing > with similar systems, a tool known as GADGET is often used for geometry > optimizations (see reference below). It seems that this tool, written in > python, is designed to work in conjunction with VASP itself.
Dear Alex, QE includes several optimization methods, one based on the BFGS algorithm and a few based on damped dynamics. On the otehr hand, I could not get a very clear description of what GADGET is supposed to do and it is not publicly available. All I could guess for mthe paper you cite, is that it runs VASP repeatedly and uses the DIIS algorithm to optimize the configuration. In fact from some reference I could find online it appers that DIIS is just a variant of the BFGS method, slightly more efficient in some cases but slightly less in others. My opinion is that just doing a geometry optimization with QE using the default setting is probably pretty much the same as doing a VASP+GADGET optimization, although I cannot be 100% sure. best regards -- Lorenzo Paulatto IdR @ IMPMC/UPMC CNRS & Universit? Paris 6 phone: +33 (0)1 44275 084 / skype: paulatz www: http://www-int.impmc.upmc.fr/~paulatto/ mail: 23-24/4?14 Bo?te courrier 115, 4 place Jussieu 75252 Paris C?dex 05
