@@ -56,11 +56,26 @@
on your machine. Since a number of Fortran 2003 features are used in the code,
it is recommended that you use the latest version of whatever compiler you
choose. For gfortran, it is recommended that you use version 4.5.0 or above.
+
If you are using Debian or a Debian derivative such as Ubuntu, you can install
+the gfortran compiler using the following command:
+
sudo apt-get install gfortran
+
+
+
Warning
+
The runtime preformance with the Intel Fortran compiler and PGI
+Fortran compiler will likely exceed that of the gfortran compiler. Compiling
+with high optimization on the gfortran compiler may make up for some of the
+performance difference
+
To compile with support for parallel runs on a distributed-memory architecture,
you will need to have a valid implementation of MPI installed on your
machine. The code has been tested and is known to work with the latest versions
-of both OpenMPI and MPICH2. You may use older versions of MPI implementations at
-your own risk.
+of both OpenMPI and MPICH2. You may use older versions of MPI implementations
+at your own risk. OpenMPI and/or MPICH2 can be installed on Debian derivatives
+with:
+
Enables parallel runs using the Message Passing Interface. Users should
also set the MPI root directory by setting the MPI variable further down in
the Makefile.
-
USE_MPI
+
USE_OPENMP
Enables parallel runs on shared-memory architecture using OpenMP threading.
USE_COARRAY
Enables parallel runs using Fortran 2008 coarrays.
+
+
Note
+
OpenMC does not yet support parallelism using OpenMP or Fortran 2008
+coarrays.
To assemble a complete model for OpenMC, one needs to create separate XML files
-for the geometry, materails, and settings. Additionally, an optional tallies XML
+for the geometry, materials, and settings. Additionally, an optional tallies XML
file specifies physical quantities to be tallied. OpenMC expects that these
files are called:
The geometry in OpenMC is described using constructive solid geometry (CSG),
+also sometimes referred to as combinatorial geometry. CSG allows a user to
+create complex objects using Boolean operators on a set of simpler surfaces. In
+the geometry model, each unique closed volume in defined by its bounding
+surfaces. In OpenMC, most quadratic surfaces can be modeled and used as
+bounding surfaces.
+
Every geometry.xml must have an XML declaration at the beginning of the file and
+a root element named geometry. Within the root element the user can define any
+number of cells, surfaces, and lattices. Let us look at the following example:
At the beginning of this file is a comment, denoted by a tag starting with
+<!-- and ending with -->. Comments, as well as any other type of input,
+may span multiple lines. One convenient feature of the XML input format is that
+sub-elements of the cell and surface elements can also be equivalently
+expressed of attributes of the original element, e.g. the geometry file above
+could be written as:
+
<?xml version="1.0">
+<geometry>
+ <!-- This is a comment -->
+
+ <surface uid="1" type="sphere" coeffs="0.0 0.0 0.0 5.0" boundary="vacuum" />
+ <cell uid="1" universe="0" material="1" surfaces="-1" />
+
+</geometry>
+
Types of surfaces:
x-plane
@@ -138,7 +181,7 @@ R^2"/>. The coefficients specified are “Table Of Contents