Efficient implementation of the Lanczos method for magnetic systems

Schnack J, Hage P, Schmidt H-J. Efficient implementation of the Lanczos method for magnetic systems. Journal of Computational Physics. 2008;227(9):4512-4517.Numerically exact investigations of interacting spin systems provide a major tool for an understanding of their magnetic properties. For medium size systems the approximate Lanczos diagonalization is the most common method. In this article we suggest two improvements: efficient basis coding in subspaces and simple restructuring for openMP parallelization. (C) 2008 Elsevier Inc. All rights reserved