> Dear SIESTA users, > > could you please explain me the sense of MeshCutoff parameter in SIESTA? > The manual is short in this respect:
Dear Ruslan, check the basic Siesta paper, J.Phys.Cond.Mat. 14 (2002) p.2745 notably section 6, "Grid integrals" > I can understand energy cutoff parameter in plane-wave based codes like > VASP, > it just controls the number of plane waves used to render wavefunctions. > Thus, in VASP it actually controls the accuracy of calculation. > But SIESTA is based on atomic orbitals. > So what this parameter actually does in SIESTA? It does not affect the size of matrix to diagonalize, but affects the accuracy of calculation. > Should the calculation be converged relative to this parameter? Yes if you care about accurate total energy and/or forces. > Any recommendations? Check tutorials on the Siesta web page, e.g. Lyon 2007, "Systematic convergence for realistic projects" (D. Sanchez-Portal) Best regards Andrei
