Wc. Oliveira et Ln. Oliveira, GENERALIZED NUMERICAL RENORMALIZATION-GROUP METHOD TO CALCULATE THE THERMODYNAMICAL PROPERTIES OF IMPURITIES IN METALS, Physical review. B, Condensed matter, 49(17), 1994, pp. 11986-11994
A dimensionless discretization parameter LAMBDA controls the accuracy
and the computational cost of numerical renormalization-group calculat
ions. For reliable computations of thermodynamical properties of impur
ities in metals, the upper bound LAMBDA less-than-or-equal-to 3 has lo
ng been established. This report discusses a generalization that raise
s the limit to LAMBDA = 10, yielding the same accuracy with significan
tly smaller computational cost.