diff --git a/var/spack/repos/builtin/packages/lammps/package.py b/var/spack/repos/builtin/packages/lammps/package.py
index 62e495fb5c..7d3df3e7cb 100644
--- a/var/spack/repos/builtin/packages/lammps/package.py
+++ b/var/spack/repos/builtin/packages/lammps/package.py
@@ -60,11 +60,19 @@ def url_for_version(self, version):
     supported_packages = ['asphere', 'body', 'class2', 'colloid', 'compress',
                           'coreshell', 'dipole', 'granular', 'kspace',
                           'kokkos', 'latte', 'manybody', 'mc', 'meam', 'misc',
-                          'molecule', 'mpiio', 'peri', 'poems', 'python',
-                          'qeq', 'replica', 'rigid', 'shock', 'snap', 'spin',
-                          'srd', 'user-atc', 'user-h5md', 'user-lb',
-                          'user-meamc', 'user-misc', 'user-netcdf', 'user-omp',
-                          'user-reaxc', 'voronoi', 'opt']
+                          'mliap', 'molecule', 'mpiio', 'opt', 'peri', 'poems',
+                          'python', 'qeq', 'replica', 'rigid', 'shock', 'snap',
+                          'spin', 'srd', 'user-atc', 'user-adios',
+                          'user-awpmd', 'user-bocs', 'user-cgsdk',
+                          'user-colvars', 'user-diffraction', 'user-dpd',
+                          'user-drude', 'user-eff', 'user-fep', 'user-h5md',
+                          'user-lb', 'user-manifold', 'user-meamc',
+                          'user-mesodpd', 'user-mesont', 'user-mgpt',
+                          'user-misc', 'user-mofff', 'user-netcdf', 'user-omp',
+                          'user-phonon', 'user-plumed', 'user-ptm', 'user-qtb',
+                          'user-reaction', 'user-reaxc', 'user-sdpd',
+                          'user-smd', 'user-smtbq', 'user-sph', 'user-tally',
+                          'user-uef', 'user-yaff', 'voronoi']
 
     for pkg in supported_packages:
         variant(pkg, default=False,
@@ -110,6 +118,9 @@ def url_for_version(self, version):
     depends_on('ffmpeg', when='+ffmpeg')
     depends_on('kokkos+deprecated_code+shared@3.0', when='@20200303+kokkos')
     depends_on('kokkos+shared@3.1:', when='@20200505:+kokkos')
+    depends_on('adios2', when='+user-adios')
+    depends_on('plumed', when='+user-plumed')
+    depends_on('eigen@3:', when='+user-smd')
 
     conflicts('+cuda', when='+opencl')
     conflicts('+body', when='+poems@:20180628')
@@ -122,8 +133,22 @@ def url_for_version(self, version):
     conflicts('+user-misc', when='~manybody')
     conflicts('%gcc@9:', when='@:20200303+openmp')
     conflicts('+kokkos', when='@:20200227')
-    conflicts('+meam', when='@20181212:')
-    conflicts('+user-meamc', when='@:20181212')
+    conflicts(
+        '+meam', when='@20181212:',
+        msg='+meam was removed after @20181212, use +user-meamc instead')
+    conflicts(
+        '+user-meamc', when='@:20181212',
+        msg='+user-meamc only added @20181212, use +meam instead')
+    conflicts(
+        '+user-reaction', when='@:20200303',
+        msg='+user-reaction only supported for version 20200505 and later')
+    conflicts('+mliap', when='~snap')
+    conflicts(
+        '+adios +mpi', when='^adios2~mpi',
+        msg='With +adios, mpi setting for adios2 and lammps must be the same')
+    conflicts(
+        '+adios ~mpi', when='^adios2+mpi',
+        msg='With +adios, mpi setting for adios2 and lammps must be the same')
 
     patch("lib.patch", when="@20170901")
     patch("660.patch", when="@20170922")
@@ -193,6 +218,18 @@ def cmake_args(self):
                 args.append('-DFFTW_LIBRARY_DIRS={0}'.format(fftw_prefix.lib))
         if '+kokkos' in spec:
             args.append('-DEXTERNAL_KOKKOS=ON')
+        if '+user-adios' in spec:
+            args.append('-DADIOS2_DIR={0}'.format(self.spec['adios2'].prefix))
+        if '+user-plumed' in spec:
+            args.append('-DDOWNLOAD_PLUMED=no')
+            if '+shared' in self.spec['plumed']:
+                args.append('-DPLUMED_MODE=shared')
+            else:
+                args.append('-DPLUMED_MODE=static')
+        if '+user-smd' in spec:
+            args.append('-DDOWNLOAD_EIGEN3=no')
+            args.append('-DEIGEN3_INCLUDE_DIR={0}'.format(
+                self.spec['eigen'].prefix.include))
 
         return args