title: Exception: ERROR: Unrecognized fix style 'shake' is part of the RIGID package which is not enabled in this LAM
body: <p>I'm trying to run a <code>LAMMPS</code> script in a <code>Colab</code> environment. However, whenever I try to use the <code>fix</code> command with arguments from the <code>RIGID</code> package the console gives me the same error.</p>
  <p>I tested different installation and build methods, such as through <code>apt</code> repository and <code>CMAKE</code>:</p>
  <p><code>Method 1</code></p>
  <pre><code>    !add-apt-repository -y ppa:gladky-anton/lammps
      !add-apt-repository -y ppa:openkim/latest
      !apt update
      !apt install -y lammps-stable
  </code></pre>
  <p><code>Method 2</code></p>
  <pre><code>    !apt install -y cmake build-essential git ccache
      !rm -rf lammps
      !git clone -b release https://github.com/lammps/lammps.git mylammps
  
      !rm -rf build
      !mkdir build
      !apt install -y fftw3
      !cd build; cmake ../mylammps/cmake/presets/most.cmake -D CMAKE_INSTALL_PREFIX=/usr \
      -D CMAKE_CXX_COMPILER_LAUNCHER=ccache -D BUILD_SHARED_LIBS=on\
      -D PKG_GPU=on -D GPU_API=cuda -D LAMMPS_EXCEPTIONS=on -D PKG_BODY=on\
      -D PKG_KSPACE=on -D PKG_MOLECULE=on -D PKG_MANYBODY=on -D PKG_ASPHERE=on\
      -D PKG_EXTRA-MOLECULE=on -D PKG_KSPACE=on -D PKG_CG-DNA=on -D PKG_ATC=on\
      -D PKG_ EXTRA-FIX=on -D PKG_FIX=on\
      -D PKG_RIGID=on -D PKG_POEMS=on -D PKG_MACHDYN=on -D PKG_DPD-SMOOTH=on\
      -D PKG_PYTHON=on ../mylammps/cmake
      !cd build; make -j 2
      !cd build; make install; make install-python
  </code></pre>
  <p>I also tested it by calling an <code>external script</code> using the <code>file()</code> method and writing commands to <code>LAMMPS</code> using the <code>command()</code> method.</p>
  <p>The part of my <code>code</code> in the <code>python</code> script that returns an error is::</p>
  <pre><code>    !pip install --user mpi4py
      #!pip install lammps-cython
  </code></pre>
  <pre class="lang-py prettyprint-override"><code>    from mpi4py import MPI
      from lammps import lammps
      #from lammps import PyLammps
      #from lammps import Lammps
      import glob
      from google.colab import files
      from google.colab import drive
      L = lammps()
  </code></pre>
  <p>...</p>
  <pre class="lang-py prettyprint-override"><code>    L.command(&quot;fix            freeze teflon setforce 0.0 0.0 0.0&quot;)
      L.command(&quot;fix            fSHAKE water shake 0.0001 10 0 b 1 a 1&quot;)
      L.command(&quot;fix            fRIGID RIG rigid molecule&quot;)
  </code></pre>
  <p>Or the same rows in LAMMPS script called:</p>
  <pre><code>    #Using an external script
      !pip install --user mpi4py
      #!pip install lammps-cython
  </code></pre>
  <pre class="lang-py prettyprint-override"><code>    from mpi4py import MPI
      from lammps import lammps
      #from lammps import PyLammps
      #from lammps import Lammps
      import glob
      from google.colab import files
      from google.colab import drive
      L = lammps()
  </code></pre>
  <p>...</p>
  <pre class="lang-py prettyprint-override"><code>    L.file(input[0])
      me = MPI.COMM_WORLD.Get_rank()
      nprocs = MPI.COMM_WORLD.Get_size()
      print(&quot;Proc %d out of %d procs has&quot; % (me,nprocs),L)
      MPI.Finalize()
  </code></pre>
  <p>The output error is:</p>
  <pre><code>
      ---------------------------------------------------------------------------
      Exception                                 Traceback (most recent call last)
      &lt;ipython-input-60-a968719e9bc6&gt; in &lt;module&gt;()
            1 L = lammps()
      ----&gt; 2 L.file(input[0])
            3 me = MPI.COMM_WORLD.Get_rank()
            4 nprocs = MPI.COMM_WORLD.Get_size()
            5 print(&quot;Proc %d out of %d procs has&quot; % (me,nprocs),L)
      
      1 frames
      /usr/local/lib/python3.7/site-packages/lammps/core.py in file(self, path)
          559 
          560     with ExceptionCheck(self):
      --&gt; 561       self.lib.lammps_file(self.lmp, path)
          562 
          563   # -------------------------------------------------------------------------
      
      /usr/local/lib/python3.7/site-packages/lammps/core.py in __exit__(self, exc_type, exc_value, traceback)
           47   def __exit__(self, exc_type, exc_value, traceback):
           48     if self.lmp.has_exceptions and self.lmp.lib.lammps_has_error(self.lmp.lmp):
      ---&gt; 49       raise self.lmp._lammps_exception
           50 
           51 # -------------------------------------------------------------------------
      
      Exception: ERROR: Unrecognized fix style 'shake' is part of the RIGID package which is not enabled in this LAM
  
  </code></pre>
  <p>Any suggestions what I can do?</p>