Thank you very much for your advices. I checked that the mesh cut-off has not influence, so I think that the second hypothesis is the reason of my problem.
Cheers, Elisa On Monday, October 04, 2010 12:13:05 pm N H wrote: > I see two hypothesis: > > 1 - Some egg box effect. > > How big is your mesh cut-off? > > 2 - In your optimization, you got stuck in some local minima, but when > changed the lattice, went to another valley in the potential surface. > > > Moreover, a simple geometry optimization never ensure that you have reached > the global minimal energy. > > On Mon, Oct 4, 2010 at 12:03 PM, Elisa <[email protected]> wrote: > > Dear Siesta users, > > > > I have optimized a solid made by Aluminum nanoclusters. First I relaxed > > the atomic coordinates (MD.VaribleCell . false) and, after that, I > > relaxed the lattice together with the atomic coordinates. Then I > > obtained an optimized solid. > > > > The problem is that I did some single point calculations changing the > > lattice > > constant in order to obtain the Energy vs Volume graphic. However, I > > realized > > that some other structures with different lattice constants are lower in > > energy than my optimized solid. > > > > Do someone know what can be the reason? What I'm doing wrong? > > > > I appreciate any comment in advance !! > > > > Thanks, > > > > Elisa Jimenez Izal > > > > > > Kimika Fakultatea > > Euskal Herriko Unibertsitatea - University of The Basque Country > > P.K. 1072, 20080 Donostia > > Euskal Herria > > E-mail: [email protected] > > Phone: +34-943-015341 > > *********************************************************************** -- ******************************************************************** Elisa Jimenez Izal Kimika Fakultatea Euskal Herriko Unibertsitatea - University of The Basque Country P.K. 1072, 20080 Donostia Euskal Herria E-mail: [email protected] Phone: +34-943-015341 ***********************************************************************
