Systematic generation of finite-range atomic basis sets for linear-scaling calculations

Basis sets of atomic orbitals are very efficient for density functional calculations but lack a systematic variational convergence. We present a method to optimize numerical atomic orbitals variationally, using a single parameter to control their range. The efficiency of the basis generation scheme is tested and compared with other schemes for multiple zeta basis sets. The scheme is shown to be comparable in quality to other widely used schemes albeit offering better performance for linear-scaling computations.