[Stable] Prepare 0.1.4 release (#265)

* Prepare 0.1.4 release

* Deprecated Location: Improve Windows compatibility (pathlib) for psi4 (#266)

* Update AdaptVQE to new, stateless VQE (#222)

* fix AdaptVQE

which previously used the (now deleted) internal method _evaluate_energy of the VQE

* add reno

Co-authored-by: Steve Wood <[email protected]>

* Bump Terra min. requirement

Co-authored-by: Julien Gacon <[email protected]>
Co-authored-by: Steve Wood <[email protected]>

qiskit_nature/VERSION.txt

@@ -1 +1 @@
-0.1.3
+0.1.4

qiskit_nature/algorithms/ground_state_solvers/adapt_vqe.py

@@ -94,12 +94,10 @@ def _compute_gradients(self,
             self._ansatz.operators = self._excitation_list + [exc]
             # set the current ansatz
             vqe.ansatz = self._ansatz
-            ansatz_params = vqe.ansatz._parameter_table.keys()
-            # construct the expectation operator of the VQE
-            vqe._expect_op = vqe.construct_expectation(ansatz_params, self._main_operator)
             # evaluate energies
             parameter_sets = theta + [-self._delta] + theta + [self._delta]
-            energy_results = vqe._energy_evaluation(np.asarray(parameter_sets))
+            energy_evaluation = vqe.get_energy_evaluation(self._main_operator)
+            energy_results = energy_evaluation(np.asarray(parameter_sets))
             # compute gradient
             gradient = (energy_results[0] - energy_results[1]) / (2 * self._delta)
             res.append((np.abs(gradient), exc))

qiskit_nature/drivers/psi4d/psi4driver.py

@@ -17,6 +17,7 @@
 import subprocess
 import sys
 import tempfile
+from pathlib import Path
 from shutil import which
 from typing import Union, List, Optional
 
@@ -105,19 +106,25 @@ def run(self) -> QMolecule:
         else:
             cfg = self._config
 
-        psi4d_directory = os.path.dirname(os.path.realpath(__file__))
-        template_file = psi4d_directory + '/_template.txt'
-        qiskit_chemistry_directory = os.path.abspath(os.path.join(psi4d_directory, '../..'))
+        psi4d_directory = Path(__file__).resolve().parent
+        template_file = psi4d_directory.joinpath("_template.txt")
+        qiskit_nature_directory = psi4d_directory.parent.parent
 
         molecule = QMolecule()
 
-        input_text = cfg + '\n'
-        input_text += 'import sys\n'
-        syspath = '[\'' + qiskit_chemistry_directory + '\',\'' + '\',\''.join(sys.path) + '\']'
-
-        input_text += 'sys.path = ' + syspath + ' + sys.path\n'
-        input_text += 'from qiskit_nature.drivers.qmolecule import QMolecule\n'
-        input_text += '_q_molecule = QMolecule("{0}")\n'.format(molecule.filename)
+        input_text = cfg + "\n"
+        input_text += "import sys\n"
+        syspath = (
+            "['"
+            + qiskit_nature_directory.as_posix()
+            + "','"
+            + "','".join(Path(p).as_posix() for p in sys.path)
+            + "']"
+        )
+
+        input_text += "sys.path = " + syspath + " + sys.path\n"
+        input_text += "from qiskit_nature.drivers.qmolecule import QMolecule\n"
+        input_text += '_q_molecule = QMolecule("{0}")\n'.format(Path(molecule.filename).as_posix())
 
         with open(template_file, 'r') as file:
             input_text += file.read()

releasenotes/notes/fix-adapt-vqe-c9df0c06ea352b91.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fix :class:`~qiskit_nature.algorithms.AdaptVQE` after the update of 
+    :class:`~qiskit.algorithms.VQE` which deleted the internal ``_energy_evaluation``
+    method that Adapt-VQE was relying on.

requirements.txt

@@ -1,4 +1,4 @@
-qiskit-terra>=0.17.0
+qiskit-terra>=0.18.0
 scipy>=1.4
 numpy>=1.17
 psutil>=5