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Hi all siesters,I'm performing a convergence test before geometry optimization
for a copper-ligand (chloro and methylpyridine ligands) crystal-like structure
with periodic boundary conditions.The unit cell contains total of 62 atoms[2
copper atoms and 4 chloride atoms], in GGA-PBE scheme,Cu and Cl are DZP, while
N, C, H are all DZWhen executing the simulation, the energies and the dDmax
value didn't converged even on thefirst CG run. So I played around with the
paramters.First I applied the electronic temperature of 0.1 eV, used different
Mesh Cutoffs, different Mixing Weights, Number pulays, and even tried the
spinpolarization but yet had no luck.I was kind of frustrated, but after
looking at the tutorials in the siesta page I realized I haven't changed the
basis setSo I tuned the PAO.EnergyShift Value to 0.30 Ry, and PAO.SplitNorm to
0.20, and finally the systemconverged. But looking at the output file, the r_c
values seemed to be changed really dramatically, so I wantto find the optimum
value for the energyshift. Right now I'm trying several simulations increasing
the energyshift by 0.01 Ry,[0.21 Ry, 0.22 Ry,0.23 Ry and so on] and leaving the
SplitNorm value to 0.15The question is, is there any systematic way to
determine, or atleast predict the level of optimum energyshift for the basis
sets, or do we have to scan the energyshift value?
