Some changes to facilitate newly implemented CCSDt

.github/workflows/ci.yaml

@@ -36,7 +36,7 @@ jobs:
           python -m pip install wheel --user
           python -m pip install setuptools --upgrade --user
           python -m pip install https://github.com/BoothGroup/dyson/archive/master.zip
-          python -m pip install -e .[dmet,ebcc] --user
+          python -m pip install .[dmet,ebcc] --user
       - name: Run unit tests
         run: |
           python -m pip install pytest pytest-cov --user

examples/ewf/molecules/26-ebcc-solvers.py

@@ -8,7 +8,7 @@
 
 mol = pyscf.gto.Mole()
 mol.atom = ["N 0 0 0", "N 0 0 2"]
-mol.basis = "aug-cc-pvdz"
+mol.basis = "cc-pvdz"
 mol.output = "pyscf.out"
 mol.build()
 
@@ -24,19 +24,15 @@
 casscf = pyscf.mcscf.CASSCF(mf, 8, 10)
 casscf.kernel()
 
+# Both these alternative specifications will always use an ebcc solver.
+# emb = vayesta.ewf.EWF(mf, solver=f'EB{ansatz}',  solver_options=dict(solve_lambda=False))
+# emb = vayesta.ewf.EWF(mf, solver='ebcc', solver_options=dict(solve_lambda=False, ansatz=ansatz))
 
 def get_emb_result(ansatz, bathtype="full"):
     # Uses fastest available solver for given ansatz; PySCF if available, otherwise ebcc.
     emb = vayesta.ewf.EWF(
         mf, solver=ansatz, bath_options=dict(bathtype=bathtype), solver_options=dict(solve_lambda=False)
     )
-    # Both these alternative specifications will always use an ebcc solver.
-    # Note that the capitalization of the solver name other than the ansatz is arbitrary.
-    # emb = vayesta.ewf.EWF(mf, solver=f'EB{ansatz}', bath_options=dict(bathtype=bathtype),
-    #                      solver_options=dict(solve_lambda=False))
-    # emb = vayesta.ewf.EWF(mf, solver='ebcc', bath_options=dict(bathtype=bathtype),
-    #                      solver_options=dict(solve_lambda=False, ansatz=ansatz))
-
     with emb.iao_fragmentation() as f:
         with f.rotational_symmetry(2, "y", center=(0, 0, 1)):
             f.add_atomic_fragment(0)
@@ -45,12 +41,24 @@ def get_emb_result(ansatz, bathtype="full"):
 
 
 e_ccsd = get_emb_result("CCSD", "full")
-e_ccsdt = get_emb_result("CCSDT", "dmet")
+e_CCSDT = get_emb_result("CCSDT", "dmet")
 e_ccsdtprime = get_emb_result("CCSDt'", "full")
 
+
+# CCSDt will set DMET orbitals as active space if no CAS is specified. To use a CAS, we must specify it explicitly.
+
+# embfull = vayesta.ewf.EWF(mf, solver='ebcc', bath_options=dict(bathtype='full'), solver_options=dict(solve_lambda=False))
+# for ffull, fact in zip( embfull.loop(), emb.loop() ):
+#     f.set_cas(c_occ=ffull.cluster.c_active_occ, c_vir=ffull.cluster.c_active_vir)
+# emb.kernel()
+e_CCSDt_ = get_emb_result("CCSDt", "dmet")
+e_CCSDt = get_emb_result("CCSDt", "full")
+
 print("E(HF)=                                           %+16.8f Ha" % mf.e_tot)
 print("E(CASCI)=                                        %+16.8f Ha" % casci.e_tot)
 print("E(CASSCF)=                                       %+16.8f Ha" % casscf.e_tot)
 print("E(CCSD, complete)=                               %+16.8f Ha" % e_ccsd)
-print("E(emb. CCSDT, DMET CAS)=                         %+16.8f Ha" % e_ccsdt)
+print("E(emb. CCSDT, DMET CAS)=                         %+16.8f Ha" % e_CCSDT)
+print("E(emb. CCSDt, DMET CAS)=                         %+16.8f Ha" % e_CCSDt_)
 print("E(emb. CCSDt', complete+DMET active space)=      %+16.8f Ha" % e_ccsdtprime)
+print("E(emb. CCSDt, complete+DMET active space)=       %+16.8f Ha" % e_CCSDt)

vayesta/core/qemb/qemb.py

@@ -1574,7 +1574,7 @@ def _check_fragmentation(self, complete_occupied=True, complete_virtual=True, to
         for s in range(nspin):
             nmo_s = tspin(self.nmo, s)
             nelec_s = tspin(nelec, s)
-            fragments = self.get_fragments(active=True, flags=dict(is_secfrag=False))
+            fragments = self.get_fragments(contributes=True, flags=dict(is_secfrag=False))
             if not fragments:
                 return False
             c_frags = np.hstack([tspin(x.c_frag, s) for x in fragments])

vayesta/ewf/fragment.py

@@ -306,7 +306,8 @@ def get_solver_options(self, solver):
         has_actspace = (
             (solver == "TCCSD")
             or ("CCSDt'" in solver)
-            or (solver.upper() == "EBCC" and self.opts.solver_options["ansatz"] == "CCSDt'")
+            or ("CCSDt" in solver)
+            or (solver.upper() == "EBCC" and self.opts.solver_options["ansatz"] in ["CCSDt", "CCSDt'"])
         )
         if has_actspace:
             # Set CAS orbitals

vayesta/solver/ebcc.py

@@ -61,7 +61,7 @@ def add_nonull_opt(d, key, newkey):
                 d[newkey] = val
 
         opts = {}
-        for key, newkey in zip(["max_cycle", "conv_tol", "conv_tol_normt"], ["max_cycle", "e_tol", "t_tol"]):
+        for key, newkey in zip(["max_cycle", "conv_tol", "conv_tol_normt"], ["max_iter", "e_tol", "t_tol"]):
             add_nonull_opt(opts, key, newkey)
         return opts
 
@@ -225,7 +225,14 @@ class Options(UEBCC_Solver.Options, EB_REBCC_Solver.Options):
 
     def get_couplings(self):
         # EBCC wants contribution  g_{xpq} p^\\dagger q b; need to transpose to get this contribution.
-        return tuple([x.transpose(0, 2, 1) for x in self.hamil.couplings])
+        #return tuple([x.transpose(0, 2, 1) for x in self.hamil.couplings])
+        # EBCC now wants an array, with spin as the first index
+        assert(np.allclose(self.hamil.couplings[0].shape, self.hamil.couplings[1].shape))
+        sh = self.hamil.couplings[0].shape
+        g = np.zeros((2, sh[0], sh[2], sh[1]), dtype=self.hamil.couplings[0].dtype)
+        g[0,:,:,:] = self.hamil.couplings[0].transpose(0,2,1)
+        g[1,:,:,:] = self.hamil.couplings[1].transpose(0,2,1)
+        return g 
 
     def construct_wavefunction(self, mycc, mo, mbos=None):
         self.wf = EBCC_WaveFunction(

vayesta/solver/hamiltonian.py

@@ -360,8 +360,9 @@ def pad(a, diag_val):
 
         clusmf.get_hcore = lambda *args, **kwargs: heff
         if overwrite_fock:
-            clusmf.get_fock = lambda *args, **kwargs: pad_to_match(
+            clusmf.get_fock = lambda *args, **kwargs: np.asarray(pad_to_match(
                 self.get_fock(with_vext=True, use_seris=not force_bare_eris), dummy_energy
+                )
             )
             clusmf.get_veff = lambda *args, **kwargs: np.array(clusmf.get_fock(*args, **kwargs)) - np.array(
                 clusmf.get_hcore()
@@ -639,7 +640,7 @@ def get_fock(self, with_vext=True, use_seris=True, with_exxdiv=False):
                 + einsum("iipq->pq", gab[oa, oa])  # Coulomb
                 - einsum("ipqi->pq", gbb[ob, :, :, ob])
             )  # Exchange
-            fock = ((fock[0] + dfa), (fock[1] + dfb))
+            fock = np.asarray(((fock[0] + dfa), (fock[1] + dfb)))
 
         return fock
 

vayesta/tests/solver/test_ebcc.py

@@ -103,6 +103,9 @@ def test_rccsdtprime_water_sto3g_dmet(self):
     def test_uccsdtprime_water_sto3g_dmet(self):
         return self._test("water_sto3g", "uhf", "CCSDt'", "CCSDT", bathtype="dmet", setcas=False)
 
+    def test_uCCSDt_water_sto3g_dmet(self):
+        return self._test("water_sto3g", "uhf", "CCSDt", "CCSDT", bathtype="dmet", setcas=False)
+
     @pytest.mark.slow
     def test_rccsdtprime_h4_sto3g_setcas_full(self):
         return self._test("h4_sto3g", "rhf", "CCSDt'", "CCSDT", bathtype="full", setcas=True)