diff --git a/var/spack/repos/builtin/packages/qmcpack/package.py b/var/spack/repos/builtin/packages/qmcpack/package.py
index 67041e455a..06eaf10996 100644
--- a/var/spack/repos/builtin/packages/qmcpack/package.py
+++ b/var/spack/repos/builtin/packages/qmcpack/package.py
@@ -54,22 +54,29 @@ class Qmcpack(CMakePackage, CudaPackage):
     variant('gui', default=False,
             description='Install with Matplotlib (long installation time)')
     variant('qe', default=True,
-            description='Install with patched Quantum Espresso 6.4.0')
+            description='Install with patched Quantum Espresso 6.4.1')
 
     # cuda variant implies mixed precision variant by default, but there is
     # no way to express this in variant syntax, need something like
     # variant('+mixed', default=True, when='+cuda', description="...")
 
-    # conflicts
+    # high-level variant conflicts
     conflicts(
         '+phdf5',
         when='~mpi',
         msg='Parallel collective I/O requires MPI-enabled QMCPACK. '
         'Please add "~phdf5" to the Spack install line for serial QMCPACK.')
 
-    conflicts('+soa',
-              when='+cuda',
-              msg='QMCPACK SOA variant does not exist for CUDA')
+    conflicts(
+        '+soa',
+        when='+cuda@:3.4.0',
+        msg='QMCPACK CUDA+SOA variant does not exist prior to v. 3.5.0.')
+
+    conflicts(
+        '+qe',
+        when='~mpi',
+        msg='Serial QMCPACK with serial QE converter not supported. '
+        'Configure in serial QE + serial HDF5 will not run correctly.')
 
     conflicts('^openblas+ilp64',
               msg='QMCPACK does not support OpenBLAS 64-bit integer variant')
@@ -110,12 +117,11 @@ class Qmcpack(CMakePackage, CudaPackage):
     depends_on('mpi', when='+mpi')
 
     # HDF5
-    depends_on('hdf5+hl+fortran', when='+qe')
-    depends_on('hdf5+hl+fortran+mpi', when='+qe+mpi')
-    depends_on('hdf5+hl+fortran~mpi', when='+qe~mpi')
-    depends_on('hdf5~hl~fortran', when='~qe')
-    depends_on('hdf5~hl~fortran+mpi', when='~qe+mpi')
-    depends_on('hdf5~hl~fortran~mpi', when='~qe~mpi')
+    depends_on('hdf5~mpi', when='~phdf5')
+    depends_on('hdf5+mpi', when='+phdf5')
+    depends_on('hdf5+hl+fortran~mpi', when='+qe~phdf5')
+    depends_on('hdf5+hl+fortran+mpi', when='+qe+phdf5')
+
     # Math libraries
     depends_on('blas')
     depends_on('lapack')
@@ -138,11 +144,11 @@ class Qmcpack(CMakePackage, CudaPackage):
     patch_checksum = '57cb1b06ee2653a87c3acc0dd4f09032fcf6ce6b8cbb9677ae9ceeb6a78f85e2'
     depends_on('quantum-espresso@6.4.1+mpi hdf5=parallel',
                patches=patch(patch_url, sha256=patch_checksum),
-               when='+qe+mpi', type='run')
+               when='+qe+phdf5', type='run')
 
-    depends_on('quantum-espresso@6.4.1~scalapack~mpi hdf5=serial',
+    depends_on('quantum-espresso@6.4.1+mpi hdf5=serial',
                patches=patch(patch_url, sha256=patch_checksum),
-               when='+qe~mpi', type='run')
+               when='+qe~phdf5', type='run')
 
     # Backport several patches from recent versions of QMCPACK
     # The test_numerics unit test is broken prior to QMCPACK 3.3.0
@@ -349,38 +355,35 @@ def install(self, spec, prefix):
     # QMCPACK 3.6.0 install directory structure changed, thus there
     # thus are two version of the setup_environment method
     @when('@:3.5.0')
-    def setup_environment(self, spack_env, run_env):
+    def setup_run_environment(self, env):
         """Set-up runtime environment for QMCPACK.
         Set PYTHONPATH for basic analysis scripts and for Nexus."""
-        run_env.prepend_path('PYTHONPATH', self.prefix.nexus)
+        env.prepend_path('PYTHONPATH', self.prefix.nexus)
 
     @when('@3.6.0:')
-    def setup_environment(self, spack_env, run_env):
+    def setup_run_environment(self, env):
         """Set-up runtime environment for QMCPACK.
         Set PYTHONPATH for basic analysis scripts and for Nexus. Binaries
         are in the  'prefix' directory instead of 'prefix.bin' which is
         not set by the default module environment"""
-        run_env.prepend_path('PATH', self.prefix)
-        run_env.prepend_path('PYTHONPATH', self.prefix)
+        env.prepend_path('PATH', self.prefix)
+        env.prepend_path('PYTHONPATH', self.prefix)
 
     @run_after('build')
     @on_package_attributes(run_tests=True)
-    def check(self):
+    def check_install(self):
         """Run ctest after building binary.
         It can take over 24 hours to run all the regression tests, here we
-        only run the unit tests and short tests. If the unit tests fail,
-        the QMCPACK installation aborts. On the other hand, the short tests
-        are too strict and often fail, but are still useful to run. In the
-        future, the short tests will be more reasonable in terms of quality
-        assurance (i.e. they will not be so strict), but will be sufficient to
-        validate QMCPACK in production."""
+        only run the unit tests and deterministic tests. If the unit tests
+        fail, the QMCPACK installation aborts. If the deterministic tests
+        fails, QMCPACK will still install and emit a warning message."""
 
         with working_dir(self.build_directory):
-            ctest('-L', 'unit')
+            ctest('-R', 'unit')
             try:
-                ctest('-R', 'short')
+                ctest('-R', 'deterministic', '-LE', 'unstable')
             except ProcessError:
-                warn  = 'Unit tests passed, but short tests have failed.\n'
-                warn += 'Please review failed tests before proceeding\n'
-                warn += 'with production calculations.\n'
+                warn  = 'Unit tests passed, but deterministic tests failed.\n'
+                warn += 'Please report this failure to:\n'
+                warn += 'https://github.com/QMCPACK/qmcpack/issues'
                 tty.msg(warn)