GENERALIZED NUMERICAL RENORMALIZATION-GROUP METHOD TO CALCULATE THE THERMODYNAMICAL PROPERTIES OF IMPURITIES IN METALS

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.