Dear All,<br><br>I have written a little DMFT code using the ALPS CTQMC 
impurity solver. The code accepts an arbitrary Hamiltonian (eventually 
with the goal of doing some form of LDA+DMFT, currently just a model 
tight-binding Hamiltonian).<br>
<br>Firstly, I was wondering what might be done to address the large 
amount of noise in the tail of the self energy (after the first 20 or so
 Matsubara frequencies, the noise is a couple of orders of magnitude 
larger than the &quot;signal&quot;). I suppose it is not surprising that 
subtracting the inverses of two small numbers would lead to this sort of
 thing.<br>
<br>Secondly, the type of lattice (a Bethe lattice by default in the 
ALPS dmft code) seems to enter into the picture via a set of three 
constants in the Fourier transforms. For the forward transform, these 
seem to be boundary terms in a numerical integration-by-parts method. 
They also appear in the backward transform, although it is less clear to
 me what their function might be. I was also wondering, if it does not 
exceed the scope of a mailing list query, if there are other places in 
the provided dmft code in which the Bethe lattice is tacitly assumed.<br>
<br>Any help would be greatly appreciated.<br><br>Regards,<br><br>Hunter<br clear="all"><br>-- <br>Hunter Sims<br>Center for Materials for Information Technology<br>University of Alabama<br>Box 870209<br>Tuscaloosa AL 35487-0209<br>
<br>205-310-9369<br>