Polynomially scaling spin dynamics II: further state-space compression using Krylov subspace techniques and zero track elimination

J Magn Reson. 2008 Nov;195(1):45-51. doi: 10.1016/j.jmr.2008.08.008. Epub 2008 Aug 27.


We extend the recently proposed state-space restriction (SSR) technique for quantum spin dynamics simulations [Kuprov et al., J. Magn. Reson. 189 (2007) 241-250] to include on-the-fly detection and elimination of unpopulated dimensions from the system density matrix. Further improvements in spin dynamics simulation speed, frequently by several orders of magnitude, are demonstrated. The proposed zero track elimination (ZTE) procedure is computationally inexpensive, reversible, numerically stable and easy to add to any existing simulation code. We demonstrate that it belongs to the same family of Krylov subspace techniques as the well-known Lanczos basis pruning procedure. The combined SSR+ZTE algorithm is recommended for simulations of NMR, EPR and Spin Chemistry experiments on systems containing between 10 and 10(4) coupled spins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms*
  • Computer Simulation
  • Data Compression / methods*
  • Magnetic Resonance Spectroscopy / methods*
  • Models, Chemical*
  • Spin Labels


  • Spin Labels