Dear Herbert, Thank you very much for your orientation. Cheers, Elisa On Monday, October 04, 2010 01:22:13 pm Herbert Fruchtl wrote: > Dear Elisa, > > No optimizer can guarantee to find the global minimum. If there is an > energy barrier between the ones you find with different methods, then the > optimization will find the one closest (i.e. on the same side of the > barrier) one to the starting structure. > > If they are very close and there is no barrier between them, it's either > not fully converged, or there is an error (in the input or the program). > Note that the default for MD.NumCGsteps (if you use the CG optimizer; I > don't remember the ones for other methods) is a bit low, so check first if > it converged. > > Cheers, > > Herbert > > Elisa 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 ***********************************************************************
