Allow to turn off AO symmetry for PBC KS calculations (pyscf#1905)

* allow turning off AO symmetry for PBC DFT

* add test

examples/pbc/20-k_points_scf_ksymm.py

@@ -35,6 +35,12 @@
 kmf.xc = 'camb3lyp'
 kmf.kernel()
 
+# By default, the mean-field calculation will use symmetry-adapted
+# crystalline orbitals whenever possible. This can be turned off manually
+# when instantiating the mean-field object.
+kmf = scf.KRHF(cell, kpts, use_ao_symmetry=False)
+kmf.kernel()
+
 #
 # The mean-field object with k-point symmetry can be converted back to
 # the correponding non-symmetric mean-field object

pyscf/pbc/dft/krks_ksymm.py

@@ -151,8 +151,9 @@ class KsymAdaptedKRKS(krks.KRKS, khf_ksymm.KRHF):
     get_init_guess = khf_ksymm.KRHF.get_init_guess
 
     def __init__(self, cell, kpts=libkpts.KPoints(), xc='LDA,VWN',
-                 exxdiv=getattr(__config__, 'pbc_scf_SCF_exxdiv', 'ewald')):
-        khf_ksymm.KRHF.__init__(self, cell, kpts, exxdiv=exxdiv)
+                 exxdiv=getattr(__config__, 'pbc_scf_SCF_exxdiv', 'ewald'),
+                 **kwargs):
+        khf_ksymm.KRHF.__init__(self, cell, kpts, exxdiv=exxdiv, **kwargs)
         rks.KohnShamDFT.__init__(self, xc)
 
     def dump_flags(self, verbose=None):

pyscf/pbc/dft/krkspu.py

@@ -247,7 +247,7 @@ class KRKSpU(krks.KRKS):
 
     def __init__(self, cell, kpts=np.zeros((1,3)), xc='LDA,VWN',
                  exxdiv=getattr(__config__, 'pbc_scf_SCF_exxdiv', 'ewald'),
-                 U_idx=[], U_val=[], C_ao_lo='minao', minao_ref='MINAO'):
+                 U_idx=[], U_val=[], C_ao_lo='minao', minao_ref='MINAO', **kwargs):
         """
         DFT+U args:
             U_idx: can be
@@ -264,7 +264,7 @@ def __init__(self, cell, kpts=np.zeros((1,3)), xc='LDA,VWN',
                      string, in 'minao'.
             minao_ref: reference for minao orbitals, default is 'MINAO'.
         """
-        super(self.__class__, self).__init__(cell, kpts, xc=xc, exxdiv=exxdiv)
+        super(self.__class__, self).__init__(cell, kpts, xc=xc, exxdiv=exxdiv, **kwargs)
 
         set_U(self, U_idx, U_val)
 

pyscf/pbc/dft/krkspu_ksymm.py

@@ -32,10 +32,10 @@ class KsymAdaptedKRKSpU(krks_ksymm.KRKS):
     @lib.with_doc(krkspu.KRKSpU.__init__.__doc__)
     def __init__(self, cell, kpts=libkpts.KPoints(), xc='LDA,VWN',
                  exxdiv=getattr(__config__, 'pbc_scf_SCF_exxdiv', 'ewald'),
-                 U_idx=[], U_val=[], C_ao_lo='minao', minao_ref='MINAO'):
+                 U_idx=[], U_val=[], C_ao_lo='minao', minao_ref='MINAO', **kwargs):
         krkspu.KRKSpU.__init__(self, cell, kpts=kpts, xc=xc, exxdiv=exxdiv,
                                U_idx=U_idx, U_val=U_val, C_ao_lo=C_ao_lo,
-                               minao_ref=minao_ref)
+                               minao_ref=minao_ref, **kwargs)
 
 KRKSpU = KsymAdaptedKRKSpU
 

pyscf/pbc/dft/kuks_ksymm.py

@@ -147,8 +147,9 @@ class KsymAdaptedKUKS(kuks.KUKS, kuhf_ksymm.KUHF):
     _finalize = kuhf_ksymm.KUHF._finalize
 
     def __init__(self, cell, kpts=libkpts.KPoints(), xc='LDA,VWN',
-                 exxdiv=getattr(__config__, 'pbc_scf_SCF_exxdiv', 'ewald')):
-        kuhf_ksymm.KUHF.__init__(self, cell, kpts, exxdiv=exxdiv)
+                 exxdiv=getattr(__config__, 'pbc_scf_SCF_exxdiv', 'ewald'),
+                 **kwargs):
+        kuhf_ksymm.KUHF.__init__(self, cell, kpts, exxdiv=exxdiv, **kwargs)
         rks.KohnShamDFT.__init__(self, xc)
 
     def dump_flags(self, verbose=None):

pyscf/pbc/dft/kukspu.py

@@ -133,7 +133,7 @@ class KUKSpU(kuks.KUKS):
 
     def __init__(self, cell, kpts=np.zeros((1,3)), xc='LDA,VWN',
                  exxdiv=getattr(__config__, 'pbc_scf_SCF_exxdiv', 'ewald'),
-                 U_idx=[], U_val=[], C_ao_lo='minao', minao_ref='MINAO'):
+                 U_idx=[], U_val=[], C_ao_lo='minao', minao_ref='MINAO', **kwargs):
         """
         DFT+U args:
             U_idx: can be
@@ -150,7 +150,7 @@ def __init__(self, cell, kpts=np.zeros((1,3)), xc='LDA,VWN',
                      string, in 'minao'.
             minao_ref: reference for minao orbitals, default is 'MINAO'.
         """
-        super(self.__class__, self).__init__(cell, kpts, xc=xc, exxdiv=exxdiv)
+        super(self.__class__, self).__init__(cell, kpts, xc=xc, exxdiv=exxdiv, **kwargs)
 
         set_U(self, U_idx, U_val)
 

pyscf/pbc/dft/kukspu_ksymm.py

@@ -32,10 +32,10 @@ class KsymAdaptedKUKSpU(kuks_ksymm.KUKS):
     @lib.with_doc(kukspu.KUKSpU.__init__.__doc__)
     def __init__(self, cell, kpts=libkpts.KPoints(), xc='LDA,VWN',
                  exxdiv=getattr(__config__, 'pbc_scf_SCF_exxdiv', 'ewald'),
-                 U_idx=[], U_val=[], C_ao_lo='minao', minao_ref='MINAO'):
+                 U_idx=[], U_val=[], C_ao_lo='minao', minao_ref='MINAO', **kwargs):
         kukspu.KUKSpU.__init__(self, cell, kpts=kpts, xc=xc, exxdiv=exxdiv,
                                U_idx=U_idx, U_val=U_val, C_ao_lo=C_ao_lo,
-                               minao_ref=minao_ref)
+                               minao_ref=minao_ref, **kwargs)
 
 KUKSpU = KsymAdaptedKUKSpU
 

pyscf/pbc/dft/test/test_krks_ksym.py

@@ -116,6 +116,18 @@ def test_kuks_monkhorst(self):
         kumf.kernel()
         self.assertAlmostEqual(kumf.e_tot, kumf0.e_tot, 6)
 
+    def test_krks_symorb(self):
+        cell1 = cell.copy()
+        cell1.build(symmorphic=True)
+        kpts = cell1.make_kpts([2,2,2], with_gamma_point=True,space_group_symmetry=True)
+        kmf = pscf.KRKS(cell1, kpts=kpts).run()
+        kmf1 = pscf.KRKS(cell1, kpts=kpts, use_ao_symmetry=False).run()
+        self.assertAlmostEqual(kmf.e_tot, kmf1.e_tot, 7)
+        assert abs(kmf.mo_coeff[0].orbsym - np.asarray([0, 4, 4, 4, 4, 4, 4, 0])).sum() == 0
+        assert abs(kmf.mo_coeff[1].orbsym - np.asarray([0, 3, 4, 4, 0, 3, 4, 4])).sum() == 0
+        assert abs(kmf.mo_coeff[2].orbsym - np.asarray([0, 0, 2, 2, 0, 2, 2, 0])).sum() == 0
+        assert getattr(kmf1.mo_coeff[0], 'orbsym', None) is None
+
     def test_rsh(self):
         kpts0 = He.make_kpts(nk, with_gamma_point=False)
         kmf0 = krks.KRKS(He, kpts=kpts0)

pyscf/pbc/scf/test/test_khf_ksym.py

@@ -87,11 +87,12 @@ def test_krhf_symorb(self):
         cell1.build(symmorphic=True)
         kpts = cell1.make_kpts([2,2,2], with_gamma_point=True,space_group_symmetry=True)
         kmf = pscf.KRHF(cell1, kpts=kpts).run()
-        kmf1 = pscf.KRHF(cell1, kpts=kpts, use_ao_symmetry=True).run()
+        kmf1 = pscf.KRHF(cell1, kpts=kpts, use_ao_symmetry=False).run()
         self.assertAlmostEqual(kmf.e_tot, kmf1.e_tot, 7)
-        assert abs(kmf1.mo_coeff[0].orbsym - np.asarray([0, 4, 4, 4, 4, 4, 4, 0])).sum() == 0
-        assert abs(kmf1.mo_coeff[1].orbsym - np.asarray([0, 3, 4, 4, 0, 3, 4, 4])).sum() == 0
-        assert abs(kmf1.mo_coeff[2].orbsym - np.asarray([0, 0, 2, 2, 0, 2, 2, 0])).sum() == 0
+        assert abs(kmf.mo_coeff[0].orbsym - np.asarray([0, 4, 4, 4, 4, 4, 4, 0])).sum() == 0
+        assert abs(kmf.mo_coeff[1].orbsym - np.asarray([0, 3, 4, 4, 0, 3, 4, 4])).sum() == 0
+        assert abs(kmf.mo_coeff[2].orbsym - np.asarray([0, 0, 2, 2, 0, 2, 2, 0])).sum() == 0
+        assert getattr(kmf1.mo_coeff[0], 'orbsym', None) is None
 
     def test_kuhf_gamma_center(self):
         self.assertAlmostEqual(kumf_ksymm.e_tot, kumf0.e_tot, 7)