text: Manual analysis of an AA′BB′ or AA′XX′ system is possible, if a sufficient number of peaks are detected. The A/A′ and B/B′ chemical shifts and the several coupling constants between each spin can be accurately obtained by quantum-mechanical simulation of the spin transition probabilities, given a set of guessed chemical shift and coupling constant values, and subsequent refinement of those values by iterative spectral fitting. Several software packages are available for this purpose, a sampling of which is (in no particular order):
  * SPINEVOLUTION. Website: http://spinevolution.org
  * NMR Simulator (free online use). Website: http://www.nmrdb.org/simulator
  * WINDNMR-Pro (shareware download). Website: http://www.chem.wisc.edu/areas/reich/plt/windnmr.htm
  * SpinWorks (freeware download). Websites: http://nmrwiki.org/wiki/index.php?title=SpinWorks and http://home.cc.umanitoba.ca/~wolowiec/spinworks/index.html
  * PERCH NMR Software, Website: http://www.perchsolutions.com