
 Introduction (Site not responding. Last check: 20070918) 
  Third, the timestep size must be proportional to the spatialgrid size for numerical stability; thus, if you double the spatial resolution, you must double the number of time steps (the length of your simulation), even if you are looking at states with the same frequency as before. 
  Fourth, you only get the frequencies of the states; to get the eigenstates themselves (so that you can see what the modes look like and do calculations with them), you must run the simulation again, once for each state that you want, and for a time inversely proportional to the frequencyspacing between adjacent states (i.e. 
  A traditional disadvantage of frequencydomain methods was that you had to compute all of the lowest eigenstates, up to the desired one, even if you didn't care about the lower ones. 
 abinitio.mit.edu /mpb/doc/introduction.html (2013 words) 
