Fix BPC 0d HF tests

Author: sunqm

pyscf/pbc/scf/test/test_hf.py

@@ -268,12 +268,11 @@ def test_rhf_0d(self):
                    basis = { 'He': [[0, (0.8, 1.0)],
                                     [0, (1.0, 1.0)],
                                     [0, (1.2, 1.0)]]})
-        eref = cell.to_mol().RHF().density_fit().kernel()
+        eref = cell.to_mol().RHF().kernel()
 
         mf = cell.RHF()
         mf.with_df = pdf.AFTDF(cell)
         e1 = mf.kernel()
-        self.assertAlmostEqual(eref, -4.165713858819728, 8)
         self.assertAlmostEqual(e1, eref, 4)
 
         eref = cell.to_mol().RHF().density_fit().kernel()

pyscf/pbc/x2c/sfx2c1e.py

@@ -120,6 +120,11 @@ def __init__(self, cell, kpts=None):
         self.cell = cell
         x2c.X2C.__init__(self, cell)
 
+    def reset(self, cell=None):
+        if cell is not None:
+            self.cell = cell
+        return self
+
 class SpinFreeX2CHelper(PBCX2CHelper):
     '''1-component X2c Foldy-Wouthuysen (FW Hamiltonian  (spin-free part only)
     '''

pyscf/x2c/x2c.py

@@ -264,9 +264,10 @@ def _get_rmat(self, x=None):
         s1 = s + reduce(numpy.dot, (x.conj().T, t, x)) * (.5/c**2)
         return _get_r(s, s1)
 
-    def reset(self, mol):
+    def reset(self, mol=None):
         '''Reset mol and clean up relevant attributes for scanner mode'''
-        self.mol = mol
+        if mol is not None:
+            self.mol = mol
         return self
 
 class SpinorX2CHelper(X2CHelperBase):
@@ -725,7 +726,7 @@ def dump_flags(self, verbose=None):
             self.with_x2c.dump_flags(verbose)
         return self
 
-    def reset(self, mol):
+    def reset(self, mol=None):
         self.with_x2c.reset(mol)
         return super().reset(mol)