Hi Sarosh Ali,
please send your questions to the ALPS user list instead of personay
to me. You'll get much faster answers that way.
On 24 Dec 2007, at 13:36, sarosh ali wrote:
> I am a student of IIT Kharagpur. I am attempting to numerically
> solve a exciton-lattice system. I tried to use ALPS, using the spin-
> less fermion basis with various terms in the hamiltonian defined. I
> tried to do full-diagonalization for 3 sites chain. However, either
> our computers hung or I got errors like "cannot get quantumnumber".
> Probably, we have not set up ALPS properly or the system
> configuration here is too low.
Maybe your input files have problems. Can you post the files you use
and we can try to help.
> So, in order to solve the problem, I intend to write a C code myself
> for arbitrary number of sites on a chain. I do have a matrix
> diagonalization code. Could you please provide me with an algorithm
> for how to order the basis elements and how to label them. My basis
> is a lattice basis for two bands with electrons in the conduction
> band and holes in the valence band is as follows: | n1,n2,n3....> X |
> m1,m2,m3.....> , where ni indicates the number of electrons and mi
> the number of holes at the lattice site i. I donot want to trouble
> you with my problem. However, if you could provide me with a generic
> way to generate basis, it would be a great help.
Sorry, I just don't have the time to explain to you how to write a
complete exact diagonalization code from scratch - since this is
essentially what you ask here.
> P.S: I have another question not related to this. How to use Alps
> for quasi-particles?
What do you mean by quasi-particles? What is your model?
Matthias Troyer