Ondrej Certik wrote: > On Thu, Oct 2, 2008 at 2:09 AM, william ratcliff > <[EMAIL PROTECTED]> wrote: > >> I'l let you know how it goes. The real application is rather cute. In >> condensed matter, we often measure the elementary excitations of solids. In >> simple magnets, these excitations are spin-waves. What I'm trying to do is >> make an application so that if you have an insulator and define the >> interactions, you can predict what excitations you will measure (in the >> simple case) to fit against experimental data. If it works, it will make >> exploring different models a lot easier and definetely more fun :> I really >> appreciate the work you guys have put into this! >> > > Thanks for the info. This is exactly the kind of thing why I started > sympy couple years ago, so I am glad it's fulfilling the purpose. If > you are interested and the code is not so long, we can put it in the > examples. Having studied theoretical physics, I am interested myself > to play with your code. :) > > Ondrej > > > > > You might be interested in the following link
http://www.informaworld.com/smpp/content~content=a901881501~db=all~jumptype=rss which references the article "Geometric formulation of correlation in a many-electron system" with abstract "We present a systematic analysis of the introduction of correlation in the many-electron time-dependent problem with an accurate formulation based on geometric algebra notation. This provides a systematic definition of the configuration space, of the external potentials, of the one-electron operators for a many-electron system, and of the electron-electron interaction terms. We arrive both at a formal equation for the total energy and at the equation for the time-evolution of the wavefunction. From this, using the new geometric notation and the indistinguishability and equivalence of the electrons and the fact that we are interested either in the ground state or in states near the ground state, we formulate a variational problem from which a set of tractable equations, which self-consistently define the many-electron wavefunction and density, is obtained. The main emphasis is on the electron-electron correlation." I am referencing this since I have added a geometric algebra module to sympy. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sympy?hl=en -~----------~----~----~----~------~----~------~--~---
