diff --git a/Golden_Repo/a/AMBER/AMBER-20-gpsmpi-2020.eb b/Golden_Repo/a/AMBER/AMBER-20-gpsmkl-2020.eb
similarity index 74%
rename from Golden_Repo/a/AMBER/AMBER-20-gpsmpi-2020.eb
rename to Golden_Repo/a/AMBER/AMBER-20-gpsmkl-2020.eb
index 383b3a7b9c89af37452ca8da9bc9838595a61346..963bc7600c6680ede746291fc538d27a23d37126 100644
--- a/Golden_Repo/a/AMBER/AMBER-20-gpsmpi-2020.eb
+++ b/Golden_Repo/a/AMBER/AMBER-20-gpsmkl-2020.eb
@@ -24,7 +24,7 @@ AMBER 2020, University of California, San Francisco.
 
 site_contacts = 'Sandipan Mohanty <s.mohanty@fz-juelich.de>'
 
-toolchain = {'name': 'gpsmpi', 'version': '2020'}
+toolchain = {'name': 'gpsmkl', 'version': '2020'}
 toolchainopts = {'pic': True}
 
 builddependencies = [
@@ -32,11 +32,16 @@ builddependencies = [
     ('binutils', '2.34',),
 ]
 dependencies = [
-    ('CMake', '3.18.0'),
+    #    ('CMake', '3.18.0'),
     ('FFTW', '3.3.8'),
     ('Python', '3.8.5'),
-    ('flex', '2.6.4', '', True),
+    ('SciPy-Stack', '2020', '-Python-%(pyver)s', ('gcccoremkl', '9.3.0-2020.2.254')),
+    ('Boost', '1.74.0', '-nompi'),
+    ('flex', '2.6.3'),
+    ('NCCL', '2.8.3-1', '-CUDA-11.0'),
 ]
+# Something in the source is causing flex 2.6.4 to SEGFAULT. Keep it at 2.6.3
+# until it is fixed. /SM 2021-05-13
 
 sources = [
     'AmberTools20.tar.bz2',
@@ -46,15 +51,20 @@ sources = [
 separate_build_dir = True
 local_build_mpi_parts = "TRUE"
 local_build_cuda_parts = "TRUE"
+local_build_cuda_nccl = "TRUE"
 
 preconfigopts = "CC=gcc && CXX=g++ && COMPILER=GNU "
 preconfigopts += " && cd %(builddir)s/amber20_src && "
 preconfigopts += " ./update_amber --update && cd ../easybuild_obj && "
 
-configopts = "-DCOMPILER=GNU -DCHECK_UPDATES=OFF -DAPPLY_UPDATES=OFF "
+configopts = "-DCOMPILER=GNU -DCHECK_UPDATES=OFF -DAPPLY_UPDATES=OFF -DBUILD_GUI=FALSE "
 configopts += " -DINSTALL_TESTS=TRUE  -DMPI=%s " % local_build_mpi_parts
-configopts += " -DDOWNLOAD_MINICONDA=TRUE -DMINICONDA_USE_PY3=TRUE "
+configopts += " -DDOWNLOAD_MINICONDA=FALSE -DTRUST_SYSTEM_LIBS=TRUE "
 configopts += " -DCUDA=%s " % local_build_cuda_parts
+configopts += " -DNCCL=%s " % local_build_cuda_nccl
+buildopts = 'NVCC_GENCODE="-gencode=arch=compute_70,code=sm_70 \
+                           -gencode=arch=compute_75,code=sm_75 \
+                           -gencode=arch=compute_80,code=sm_80"'
 
 modextravars = {
     'AMBERHOME': '%(installdir)s/',
diff --git a/acls.yml b/acls.yml
index 054e0905e3bd67048040a3e2112d7a11babcb475..edb27b297ccb77c6e46dabeafdaa5dd73b38bef4 100644
--- a/acls.yml
+++ b/acls.yml
@@ -54,6 +54,9 @@ mpis:
   - name: 'OpenMPI'
     version: '4.1'
 software:
+  - name: 'AMBER'
+    owner: 'mohanty1'
+    mpi: True
   - name: 'ParaView'
     owner: 'goebbert1'
     mpi: True