On Jan 16, 2006, at 10:41 PM, Kirill Belashchenko wrote:

Dear Dr. Troyer,

I am looking for a code that can generate random spin configurations from Monte Carlo simulations for the classical Heisenberg model. I looked at the ALPS code and found that it can do the simulations, but I could not find a documented option to dump a random configuration to a file. Is there an easy way to do this? Where is this configuration stored in the code?

Thank you,

Kirill Belashchenko Assistant Professor Department of Physics and Astronomy and Center for Materials Research and Analysis University of Nebraska-Lincoln Lincoln, NE 68588-0111 Office: (402)472-2396, 214B Ferguson Hall Fax: (402)472-2879 Email: kdbel@unlserve.unl.edu

It should be no problem to add code to dump the configurations, but you might be better off just directly adding the measurements you want to the code. The best place to add code for dumping the configurations or adding extra measurements is the file mc/spins/ spinsim.h in the function SpinSim<M>::do_measurements() . The spins are stored in the vector spins_, and you might need to add an output operator to the ONMoment class in file on.h to write the spins to a text file in your preferred format. Don't hesitate ask again if you have further questions.

Best regards

Matthias Troyer