Some BugFixes (#311)

* UpCCGSD mix_sd fixed

Author: JdelArco98

.github/workflows/ci_pyquil.yml

@@ -29,8 +29,9 @@ jobs:
         python -m pip install --upgrade pip
         pip install --upgrade pytest
         pip install -r requirements.txt
-        pip install "pyquil<3.0"
+        pip install "pyquil<3.0" # needs updates
         pip install -e .
+        pip install --upgrade pip 'urllib3<2' # issues with old pyquil version otherwise
         docker pull rigetti/qvm:edge
         docker pull rigetti/quilc
         docker run --rm -itd -p 5555:5555 rigetti/quilc -R

README.md

@@ -15,7 +15,7 @@ Tequila can execute the underlying quantum expectation values on state of the ar
 
 # Installation
 Recommended Python version is 3.8-3.9.   
-Tequila supports linux, osx and windows. However, not all optional dependencies are supported on windows.
+Tequila supports linux, osx and windows. However, not all optional dependencies are supported on windows.  
 
 ## Install from PyPi
 **Do not** install like this: (Minecraft lovers excluded)

src/tequila/quantumchemistry/qc_base.py

@@ -1102,7 +1102,8 @@ def make_upccgsd_ansatz(self,
                             assume_real: bool = True,
                             hcb_optimization: bool = None,
                             spin_adapt_singles: bool = True,
-                            neglect_z=False,
+                            neglect_z: bool = False,
+                            mix_sd: bool = False,
                             *args, **kwargs):
         """
         UpGCCSD Ansatz similar as described by Lee et. al.
@@ -1127,6 +1128,10 @@ def make_upccgsd_ansatz(self,
         assume_real
             assume a real wavefunction (that is always the case if the reference state is real)
             reduces potential gradient costs from 4 to 2
+        mix_sd
+            Changes the ordering from first all doubles and then all singles excitations (DDDDD....SSSS....) to
+            a mixed order (DS-DS-DS-DS-...) where one DS pair acts on the same MOs. Useful to consider when systems
+            with high electronic correlation and system high error associated with the no Trotterized UCC.
         Returns
         -------
             UpGCCSD ansatz
@@ -1167,7 +1172,8 @@ def make_upccgsd_ansatz(self,
                 raise Exception(
                     "name={}, Singles can't be realized without mapping back to the standard encoding leave S or HCB out of the name".format(
                         name))
-
+        if hcb_optimization and mix_sd:
+            raise TequilaException("Mixed SD can not be employed together with HCB Optimization")
         # convenience
         S = "S" in name.upper()
         D = "D" in name.upper()
@@ -1178,7 +1184,8 @@ def make_upccgsd_ansatz(self,
             if include_reference:
                 U = self.prepare_reference()
             U += self.make_upccgsd_layer(include_singles=S, include_doubles=D, indices=indices, assume_real=assume_real,
-                                         label=(label, 0), spin_adapt_singles=spin_adapt_singles, *args, **kwargs)
+                                         label=(label, 0), mix_sd=mix_sd, spin_adapt_singles=spin_adapt_singles, *args,
+                                         **kwargs)
         else:
             U = QCircuit()
             if include_reference:
@@ -1197,12 +1204,14 @@ def make_upccgsd_ansatz(self,
 
         for k in range(1, order):
             U += self.make_upccgsd_layer(include_singles=S, include_doubles=D, indices=indices, label=(label, k),
-                                         spin_adapt_singles=spin_adapt_singles, neglect_z=neglect_z)
+                                         spin_adapt_singles=spin_adapt_singles, neglect_z=neglect_z, mix_sd=mix_sd)
 
         return U
 
-    def make_upccgsd_layer(self, indices, include_singles=True, include_doubles=True, assume_real=True, label=None,
-                           spin_adapt_singles: bool = True, angle_transform=None, mix_sd=False, neglect_z=False, *args,
+    def make_upccgsd_layer(self, indices, include_singles: bool = True, include_doubles: bool = True,
+                           assume_real: bool = True, label=None,
+                           spin_adapt_singles: bool = True, angle_transform=None, mix_sd: bool = False,
+                           neglect_z: bool = False, *args,
                            **kwargs):
         U = QCircuit()
         for idx in indices:
@@ -1220,7 +1229,7 @@ def make_upccgsd_layer(self, indices, include_singles=True, include_doubles=True
                                                    indices=((2 * idx[0], 2 * idx[1]), (2 * idx[0] + 1, 2 * idx[1] + 1)),
                                                    assume_real=assume_real, **kwargs)
             if include_singles and mix_sd:
-                U += self.make_upccgsd_singles(indices=[idx], assume_real=assume_real, label=label,
+                U += self.make_upccgsd_singles(indices=[(idx,)], assume_real=assume_real, label=label,
                                                spin_adapt_singles=spin_adapt_singles, angle_transform=angle_transform,
                                                neglect_z=neglect_z)