Tutorials:Parameters

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The following input parameters are common to most of the ALPS applications


Parameters for Monte Carlo simulations

Parameter Default Meaning
SEED 0 The random number seed used in the next run. After using a seed in the creation of a Monte Carlo run, this value gets incremented by one.
WORK_FACTOR 1 A factor by which the work that needs to be done for a simulation is multiplied in load balancing.


Lattice defintion

ALPS applications on lattices specify the lattice with the following three parameters

Parameter Default Meaning
LATTICE_LIBRARY lattices.xml path to a file containing lattice descriptions
LATTICE name of the lattice, specified by dimensionality, extent and unit cell.
GRAPH as an alternative to a lattice, also a specific arbitrary graph defined in the lattice library can be specified.

In addition, the lattice description can require further parameters (e.g. L or W) as specified in the lattice description file.

Model defintion

ALPS quantum lattice models can be specified using the following parameters

Parameter Default Meaning
MODEL_LIBRARY models.xml path to a file containing model descriptions</td>
MODEL name of the model (for example "spin" or "boson")

The model description can also require further parameters (e.g. S=1/2 or S=1, h=0.5 for spin models, t=1.5 or mu=0.5 for boson models) as specified in the model description file.

     </td>
   </tr>
   <tr>
     <td>T</td>
     <td>
</td> <td>the temperature</td> </tr> <tr> <td style="vertical-align: top;">BETA
</td> <td style="vertical-align: top;">
</td> <td style="vertical-align: top;">inverse of temperature (if

temperature is not given)

     </td>
   </tr>
   <tr>
     <td style="vertical-align: top;">SWEEPS
</td> <td style="vertical-align: top;">
</td> <td style="vertical-align: top;">number of Monte Carlo steps

(after thermalization)

     </td>
   </tr>
   <tr>
     <td style="vertical-align: top;">THERMALIZATION</td>
     <td style="vertical-align: top;">SWEEPS / 10</td>
     <td style="vertical-align: top;">Number of Monte Carlo sweeps for

thermalization</td>

   </tr>
 </tbody>

</table>