Hi all, I am running some calculations for a 3D structure made of carbon, using Siesta 3.2-pl-5. The executable was compiled with
gfortran using mpif90 -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic however, I am running the code serially, since the structures I'm working with have 4 or 8 atoms. My structure has a monoclinic unit cell of 4 atoms, and when I run an SCF for the atomic positions, I get appreciable forces along the basal (xy) plane of the cell, which seemed a bot strange to me. When I transformed the 4-atom monoclinic cell into an 8-atom orthorhombic one, with exactly the same structure, the forces along the basal plane were around 10^-5 eV/Ang, which was what I expected. Has anyone experienced that kind of problem? I'd like to stress that the problem is *not* the atomic positions: upon replicating the 4-atom supercell properly, I get exactly the same geometry of the 8-atom orthorhombic cell. Would anyone have a hint as to why this happens? Best regards, Marcos
