PySCF new package (#17474)

* Initial version of PySCF.

* Add master branch to xcfun library

* PySCF only compatible with specific commit of xcfun library

* Update var/spack/repos/builtin/packages/py-pyscf/package.py

Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>

* Update var/spack/repos/builtin/packages/py-pyscf/package.py

Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>

* Revert "PySCF only compatible with specific commit of xcfun library"

This reverts commit 8296005400.

* Revert "Add master branch to xcfun library"

This reverts commit f2b6998931.

* Issues conflict for xcfun library version rather than relying on a random commit.

* Add version xcfun 2.0.0a2 which is needed by PySCF.

* Remove xcfun conflict and express dependency more explictly. Add comment as to why this is necessary.

Co-authored-by: Adam J. Stewart <ajstewart426@gmail.com>

var/spack/repos/builtin/packages/py-pyscf/package.py

@@ -0,0 +1,43 @@
+# Copyright 2013-2020 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+
+from spack import *
+
+
+class PyPyscf(PythonPackage):
+    """PySCF is a collection of electronic structure programs powered
+    by Python."""
+
+    homepage = "https://sunqm.github.io/pyscf/"
+    git      = "https://github.com/pyscf/pyscf"
+
+    maintainers = ['naromero77']
+
+    version('1.7.3', tag='v1.7.3')
+
+    # dependencies
+    depends_on('cmake@2.8:', type='build')
+    depends_on('python@2.6:', type=('build', 'run'))
+    depends_on('py-numpy@1.8.0:', type=('build', 'run'))
+    depends_on('py-scipy@0.12:', type=('build', 'run'))
+    depends_on('py-h5py@2.3.0:', type=('build', 'run'))
+    depends_on('blas')
+    depends_on('libcint+coulomb_erf+f12')
+    depends_on('libxc')
+    depends_on('xcfun@:2.0.0a2')  # PySCF does not support recent version of the xcfun API'
+
+    def setup_build_environment(self, env):
+        # Tell PSCF where supporting libraries are located."
+        spec = self.spec
+
+        pyscf_search_dir = []
+        pyscf_search_dir.append(spec['blas'].prefix)
+        pyscf_search_dir.append(spec['libcint'].prefix)
+        pyscf_search_dir.append(spec['libxc'].prefix)
+        pyscf_search_dir.append(spec['xcfun'].prefix)
+        pyscf_search_dir.append(spec['xcfun'].prefix.include.XCFun)
+
+        env.set('PYSCF_INC_DIR', ":".join(pyscf_search_dir))

var/spack/repos/builtin/packages/xcfun/package.py

@@ -16,6 +16,8 @@ class Xcfun(CMakePackage):
 
     version('2.0.0a6',
             sha256='a51086490890393439f98c5e3e4e1622908fe934bbc5063b1d4363cc4c15496d')
+    version('2.0.0a2',
+            sha256='f29e80fdb5c8089fb0eeb7827659111005cb13eb42bf75fcb0c034f6bd067c31')
 
     extends('python')
     depends_on('cmake@3.11:', type='build')