Use self.ci if set for mcscf (pyscf#2342)

* use casscf.ci if set

* also fix the free kernel

* update test

* remove global mols

* update test to align with casci

* Improve error types in FCI modules

---------

Co-authored-by: Qiming Sun <[email protected]>

pyscf/fci/direct_spin0_symm.py

@@ -97,7 +97,8 @@ def get_init_guess(norb, nelec, nroots, hdiag, orbsym, wfnsym=0):
         ci0.append(x.ravel().view(direct_spin1.FCIvector))
 
     if len(ci0) == 0:
-        raise RuntimeError(f'Initial guess for symmetry {wfnsym} not found')
+        raise lib.exceptions.WfnSymmetryError(
+            f'Initial guess for symmetry {wfnsym} not found')
     return ci0
 
 def get_init_guess_cyl_sym(norb, nelec, nroots, hdiag, orbsym, wfnsym=0):
@@ -146,7 +147,8 @@ def get_init_guess_cyl_sym(norb, nelec, nroots, hdiag, orbsym, wfnsym=0):
             break
 
     if len(ci0) == 0:
-        raise RuntimeError(f'Initial guess for symmetry {wfnsym} not found')
+        raise lib.exceptions.WfnSymmetryError(
+            f'Initial guess for symmetry {wfnsym} not found')
     return ci0
 
 

pyscf/fci/direct_spin1_symm.py

@@ -237,7 +237,8 @@ def _get_init_guess(airreps, birreps, nroots, hdiag, nelec, orbsym, wfnsym=0):
         ci0.append(x.ravel().view(direct_spin1.FCIvector))
 
     if len(ci0) == 0:
-        raise RuntimeError(f'Initial guess for symmetry {wfnsym} not found')
+        raise lib.exceptions.WfnSymmetryError(
+            f'Initial guess for symmetry {wfnsym} not found')
     return ci0
 
 def get_init_guess(norb, nelec, nroots, hdiag, orbsym, wfnsym=0):
@@ -263,7 +264,8 @@ def get_init_guess(norb, nelec, nroots, hdiag, orbsym, wfnsym=0):
         ci0.append(x.ravel().view(direct_spin1.FCIvector))
 
     if len(ci0) == 0:
-        raise RuntimeError(f'Initial guess for symmetry {wfnsym} not found')
+        raise lib.exceptions.WfnSymmetryError(
+            f'Initial guess for symmetry {wfnsym} not found')
     return ci0
 
 def _validate_degen_mapping(mapping, norb):
@@ -355,7 +357,8 @@ def get_init_guess_cyl_sym(norb, nelec, nroots, hdiag, orbsym, wfnsym=0):
             break
 
     if len(ci0) == 0:
-        raise RuntimeError(f'Initial guess for symmetry {wfnsym} not found')
+        raise lib.exceptions.WfnSymmetryError(
+            f'Initial guess for symmetry {wfnsym} not found')
     return ci0
 
 def _cyl_sym_csf2civec(strs, addr, orbsym, degen_mapping):
@@ -598,8 +601,9 @@ def guess_wfnsym(solver, norb, nelec, fcivec=None, orbsym=None, wfnsym=None, **k
                 fcivec = fcivec[0]
             wfnsym1 = _guess_wfnsym_cyl_sym(fcivec, strsa, strsb, orbsym)
             if wfnsym1 != _id_wfnsym(solver, norb, nelec, orbsym, wfnsym):
-                raise RuntimeError(f'Input wfnsym {wfnsym} is not consistent with '
-                                   f'fcivec symmetry {wfnsym1}')
+                raise lib.exceptions.WfnSymmetryError(
+                    f'Input wfnsym {wfnsym} is not consistent with '
+                    f'fcivec symmetry {wfnsym1}')
             wfnsym = wfnsym1
         else:
             na, nb = strsa.size, strsb.size
@@ -617,8 +621,8 @@ def guess_wfnsym(solver, norb, nelec, fcivec=None, orbsym=None, wfnsym=None, **k
             if isinstance(fcivec, np.ndarray) and fcivec.ndim <= 2:
                 fcivec = [fcivec]
             if all(abs(c.reshape(na, nb)[mask]).max() < 1e-5 for c in fcivec):
-                raise RuntimeError('Input wfnsym {wfnsym} is not consistent with '
-                                   'fcivec coefficients')
+                raise lib.exceptions.WfnSymmetryError(
+                    'Input wfnsym {wfnsym} is not consistent with fcivec coefficients')
     return wfnsym
 
 def sym_allowed_indices(nelec, orbsym, wfnsym):
@@ -787,7 +791,7 @@ def kernel(self, h1e, eri, norb, nelec, ci0=None,
         logger.debug(self, 'Num symmetry allowed elements %d',
                      sum([x.size for x in self.sym_allowed_idx]))
         if s_idx.size == 0:
-            raise RuntimeError(
+            raise lib.exceptions.WfnSymmetryError(
                 f'Symmetry allowed determinants not found for wfnsym {wfnsym}')
 
         if wfnsym_ir > 7:

pyscf/lib/exceptions.py

@@ -20,3 +20,6 @@ class BasisNotFoundError(RuntimeError):
 
 class PointGroupSymmetryError(RuntimeError):
     pass
+
+class WfnSymmetryError(RuntimeError):
+    pass

pyscf/mcscf/casci.py

@@ -583,6 +583,8 @@ def kernel(casci, mo_coeff=None, ci0=None, verbose=logger.NOTE, envs=None):
             and "envs" pop in kernel function
     '''
     if mo_coeff is None: mo_coeff = casci.mo_coeff
+    if ci0 is None: ci0 = casci.ci
+
     log = logger.new_logger(casci, verbose)
     t0 = (logger.process_clock(), logger.perf_counter())
     log.debug('Start CASCI')

pyscf/mcscf/mc1step.py

@@ -341,6 +341,9 @@ def kernel(casscf, mo_coeff, tol=1e-7, conv_tol_grad=None,
     if callback is None:
         callback = casscf.callback
 
+    if ci0 is None:
+        ci0 = casscf.ci
+
     mo = mo_coeff
     nmo = mo_coeff.shape[1]
     ncore = casscf.ncore
@@ -853,6 +856,9 @@ def kernel(self, mo_coeff=None, ci0=None, callback=None, _kern=kernel):
             self.mo_coeff = mo_coeff
         if callback is None: callback = self.callback
 
+        if ci0 is None:
+            ci0 = self.ci
+
         self.check_sanity()
         self.dump_flags()
 

pyscf/mcscf/test/test_mc1step.py

@@ -28,7 +28,7 @@ def setUpModule():
     global mol, molsym, m, msym, mc0
     b = 1.4
     mol = gto.M(
-    verbose = 5,
+    verbose = 0,
     output = '/dev/null',
     atom = [
         ['N',(  0.000000,  0.000000, -b/2)],
@@ -42,7 +42,7 @@ def setUpModule():
     mc0 = mcscf.CASSCF(m, 4, 4).run()
 
     molsym = gto.M(
-    verbose = 5,
+    verbose = 0,
     output = '/dev/null',
     atom = [
         ['N',(  0.000000,  0.000000, -b/2)],
@@ -86,7 +86,7 @@ def test_mc1step_symm_with_x2c_scanner(self):
         self.assertAlmostEqual(mc1.e_tot, -109.02535605303684, 7)
 
     def test_0core_0virtual(self):
-        mol = gto.M(atom='He', basis='321g')
+        mol = gto.M(atom='He', basis='321g', verbose=0)
         mf = scf.RHF(mol).run()
         mc1 = mcscf.CASSCF(mf, 2, 2).run()
         self.assertAlmostEqual(mc1.e_tot, -2.850576699649737, 9)
@@ -316,14 +316,14 @@ def test_state_average_mix(self):
         mc.analyze()
         mo_coeff, civec, mo_occ = mc.cas_natorb(sort=True)
 
-        mc.kernel(mo_coeff=mo_coeff)
+        mc.kernel(mo_coeff=mo_coeff, ci0=civec)
         self.assertAlmostEqual(mc.e_states[0], -108.7506795311190, 5)
         self.assertAlmostEqual(mc.e_states[1], -108.8582272809495, 5)
         self.assertAlmostEqual(abs((civec[0]*mc.ci[0]).sum()), 1, 7)
         self.assertAlmostEqual(abs((civec[1]*mc.ci[1]).sum()), 1, 7)
 
     def test_small_system(self):
-        mol = gto.M(atom='H 0 0 0; H 0 0 .74', symmetry=True, basis='6-31g')
+        mol = gto.M(atom='H 0 0 0; H 0 0 .74', symmetry=True, basis='6-31g', verbose=0)
         mf = scf.RHF(mol).run()
         mc = mcscf.CASSCF(mf, 2, 2)
         mc.max_cycle = 5

pyscf/mcscf/test/test_n2.py

@@ -17,6 +17,7 @@
 import numpy
 from pyscf import gto
 from pyscf import scf
+from pyscf import lib
 from pyscf import mcscf
 
 def setUpModule():
@@ -166,6 +167,9 @@ def test_wfnsym(self):
         self.assertAlmostEqual(emc, -108.74508322877787, 7)
 
         mc.wfnsym = 'A2u'
+        with self.assertRaises(lib.exceptions.WfnSymmetryError):
+            mc.mc1step()
+        mc.ci = None
         emc = mc.mc1step()[0]
         self.assertAlmostEqual(emc, -108.69019443475308, 7)