Re: [SIESTA-L] Performing relaxation correctly

2007-05-01 Thread Yurko Natanzon
Dear Marcos, Thank you for your detailed explanation. But it seems to me that VariableCell=true calculations should give the same result as repeating several fized cell calculations. Do you take into account the value of stress tensor obtained in previous calculations for deciding the direction of

Re: [SIESTA-L] Performing relaxation correctly

2007-05-01 Thread Marcos Verissimo Alves
Hi Yurko, I guess the "most correct" way of doing this would be to do a search in all phase space of the possible parameters for the cell. In other words, you should relax atomic positions in fixed-cell calculations spanning the function E(a,b,c,alpha,beta,gamma), where E is the total energy, and