> However, it seems that I have
difficulty finding a systematic way of optimization
The general idea is described in the main SIESTA paper
The Siesta method for ab initio order-N materials simulation
José M. Soler, Emilio Artacho, Julian D. Gale, Alberto García, Javier
Junquera, Pablo Ordejón and Daniel Sánchez-Portal
J. Phys.: Condens. Matter 14, 2745-2779 (2002)
arXiv:cond-mat/0111138, 8 Nov 2001.
and in more details in
Systematic generation of finite-range atomic basis sets for
linear-scaling calculations
E. Anglada, J. M. Soler, J. Junquera and E. Artacho
Phys. Rev. B 66, 205101 (2002).
arXiv:cond-mat/0207548, 23 Jul 2002.
