Dear all,
1. Brilliant - exactly what I needed (been modifying the 1.3 spinmc code to get that) 2. How do we specify nvalues for Bond Type? I.e. the shell maximum radius in order to get the appropriate correlations in 1.3.3 version? What is the parameter?
Best and thanks, Kruno
--------------------------------------- Krunoslav Prsa, Ph. D. Student Laboratory for Neutron Scattering Paul Scherrer Institute and ETH-Zürich CH-5232 Villigen PSI, Switzerland tel: +41 56 310 20 91 mob: +41 76 386 17 99 ----------------------------------------
-----Original Message----- From: comp-phys-alps-users-bounces@phys.ethz.ch [mailto:comp-phys-alps-users-bounces@phys.ethz.ch] On Behalf Of Matthias Troyer Sent: Saturday, July 26, 2008 12:55 AM To: comp-phys-alps-users@phys.ethz.ch Subject: Re: [ALPS-users] correlation function+susceptibility
We have added two features for you that will be available soon in the next release:
1. if you define the parameter PRINT_SWEEPS=xxx then after xxx sweeps the configuration will be dumped, for 3D Heisenberg in 7 columns: the site index, then the spatial coordinates and then the spin components.
2. we also record the energy for each bond type. Bond type 0 will be the nearest neighbor correlation you wants, etc..
Matthias
On 21 Jul 2008, at 23:20, Fritz Koermann wrote:
The internal energy is just the short-range correlation.
Also below Tc?
Yes.
Does it also hold if one defines J_ij up to more than one shell? E.g. do other correlation functions <SiSi+j> with j=[1..number of shells] not entering the internal energy?
If they are in your model then they will contribute, but we don't have a model taking interactions to certain shells in ALPS. Is that the model you need?
Yes, I need such a model. I defined one using the lattice.xml based on a given 3d bcc cell. I built up an model including the first 10 interactions with edges starting from the center (0,0,0) to the nearest-neighbors in the corresponding shells. Now I would like to figure out how strong the short-range correlations contribute to the internal energy and, also, to the free energy respectively. For such reasons a short-order correlation function would be very interesting.
I have more physics questions: Concerning the free energy, is it possible to set the the magnetic entropy in the classical Heisenberg model to constant for T->0 in order to obtain the free energy via integration (over the internal energy)? Or should one better integrate over the heat capacity to get the entropy?
Best, Fritz Koermann
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