LMOD-QuickReference-Guide.md

@@ -5,12 +5,13 @@ The system now uses a combination of the LMOD module system and the EasyBuild au
     1. [Loading and unloading modules](#loading-and-unloading-modules)
     2. [Searching modules](#searching-modules)
     3. [Personal module collections](#personal-module-collections)
-2. [Core compiler](#core-compiler)
-3. [Toolchains](#toolchains)
+2. [Example](#Example) 
+3. [Core compiler](#core-compiler)
+4. [Toolchains](#toolchains)
     1. [Existing toolchains](#existing-toolchains)
         1. [Intel-based](#intel-based)
         2. [GCC-based](#gcc-based)
-4. [External Documentation](#external-documentation)
+5. [External Documentation](#external-documentation)
 
 ## Basics
 
@@ -112,6 +113,77 @@ To remove a specific save module collection.
 ```sh
 > module disable <collection-name>
 ```
+### Example
+
+Assume you want to know whether a package is available on the cluster, in this example LAMMPS.
+
+1. First check by using `spider` for a case-insensitive, partial-match search for the package.
+
+```
+> module spider LAMMPS 
+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+  LAMMPS:
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+    Description:
+      LAMMPS is a classical molecular dynamics code, and an acronym for Large-scale Atomic/Molecular Massively Parallel Simulator. LAMMPS has potentials for solid-state materials (metals, semiconductors) and soft matter
+      (biomolecules, polymers) and coarse-grained or mesoscopic systems. It can be used to model atoms or, more generically, as a parallel particle simulator at the atomic, meso, or continuum scale. LAMMPS runs on single processors
+      or in parallel using message-passing techniques and a spatial-decomposition of the simulation domain. The code is designed to be easy to modify or extend with new functionality. 
+
+     Versions:
+        LAMMPS/3Mar2020-Python-3.8.2-kokkos
+        LAMMPS/23Jun2022-kokkos
+
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+  For detailed information about a specific "LAMMPS" package (including how to load the modules) use the module's full name.
+  Note that names that have a trailing (E) are extensions provided by other modules.
+  For example:
+
+     $ module spider LAMMPS/23Jun2022-kokkos
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+```
+2. As shown on the last line (for the default module of that name), specifying a specific version explicitly, will list the dependencies needed to be loaded before the respective module becomes available.
+
+```
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+  LAMMPS: LAMMPS/23Jun2022-kokkos
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+    Description:
+      LAMMPS is a classical molecular dynamics code, and an acronym for Large-scale Atomic/Molecular Massively Parallel Simulator. LAMMPS has potentials for solid-state materials (metals, semiconductors) and soft matter
+      (biomolecules, polymers) and coarse-grained or mesoscopic systems. It can be used to model atoms or, more generically, as a parallel particle simulator at the atomic, meso, or continuum scale. LAMMPS runs on single processors
+      or in parallel using message-passing techniques and a spatial-decomposition of the simulation domain. The code is designed to be easy to modify or extend with new functionality. 
+
+
+    You will need to load all module(s) on any one of the lines below before the "LAMMPS/23Jun2022-kokkos" module is available to load.
+
+      GCC/10.3.0  OpenMPI/4.1.1
+ 
+    Help:
+      
+      Description
+      ===========
+      LAMMPS is a classical molecular dynamics code, and an acronym
+      for Large-scale Atomic/Molecular Massively Parallel Simulator. LAMMPS has
+      potentials for solid-state materials (metals, semiconductors) and soft matter
+      (biomolecules, polymers) and coarse-grained or mesoscopic systems. It can be
+      used to model atoms or, more generically, as a parallel particle simulator at
+      the atomic, meso, or continuum scale. LAMMPS runs on single processors or in
+      parallel using message-passing techniques and a spatial-decomposition of the
+      simulation domain. The code is designed to be easy to modify or extend with new
+      functionality.
+      
+      
+      More information
+      ================
+       - Homepage: https://www.lammps.org
+```
+
+Listed above the "Help:" line are dependencies to make that specific version available. If the package is available for different compiler and MPI combinations (or other dependencies), Lmod will list multiple lines here where each separate line lists all dependencies for that toolchain. In this example loading the corresponding `GCC` and `OpenMPI` package will work.
+
+```
+> module load GCC/10.3.0  OpenMPI/4.1.1 LAMMPS/23Jun2022-kokkos
+```
+
+**NOTE:** Even though Lmod allows to automatically unload modules of conflicting packages, such _families_ are **NOT** defined on CLAIX, to explicitly allow for loading multiple compilers into the environment.
 
 ### Core Compiler