Enable numpy array of get_k_kpts in df_jk.py

Dear all,

I found that if the user gives a set of mo_occ or mo_coeff (in numpy array form) to the kmf with GDF, the current will raise an error. 
It assume the mo_coeff, mo_occ is list of tuple.

pyscf/pbc/df/df_jk.py

@@ -296,13 +296,15 @@ def get_k_kpts(mydf, dm_kpts, hermi=1, kpts=numpy.zeros((1,3)), kpts_band=None,
     skmoR = skmo2R = None
     if not mydf.force_dm_kbuild:
         if mo_coeff is not None:
-            if isinstance(mo_coeff[0], (list, tuple)):
+            if isinstance(mo_coeff[0], (list, tuple)) or \
+                isinstance(mo_coeff[0], numpy.ndarray and mo_coeff[0] == 3):
                 mo_coeff = [mo for mo1 in mo_coeff for mo in mo1]
             if len(mo_coeff) != nset*nkpts: # wrong shape
                 log.warn('mo_coeff from dm tag has wrong shape. '
                          'Calculating mo from dm instead.')
                 mo_coeff = None
-            elif isinstance(mo_occ[0], (list, tuple)):
+            elif isinstance(mo_occ[0], (list, tuple)) or \
+                isinstance(mo_occ[0], numpy.ndarray and mo_occ[0] == 2):
                 mo_occ = [mo for mo1 in mo_occ for mo in mo1]
         if mo_coeff is not None:
             skmoR, skmoI = _format_mo(mo_coeff, mo_occ, shape=(nset,nkpts), order='F',
@@ -704,13 +706,15 @@ def get_k_kpts_kshift(mydf, dm_kpts, kshift, hermi=0, kpts=numpy.zeros((1,3)), k
     skmoR = skmo2R = None
     if not mydf.force_dm_kbuild:
         if mo_coeff is not None:
-            if isinstance(mo_coeff[0], (list, tuple)):
+            if isinstance(mo_coeff[0], (list, tuple)) or \
+                isinstance(mo_coeff[0], numpy.ndarray and mo_coeff[0] == 3):
                 mo_coeff = [mo for mo1 in mo_coeff for mo in mo1]
             if len(mo_coeff) != nset*nkpts: # wrong shape
                 log.warn('mo_coeff from dm tag has wrong shape. '
                          'Calculating mo from dm instead.')
                 mo_coeff = None
-            elif isinstance(mo_occ[0], (list, tuple)):
+            elif isinstance(mo_occ[0], (list, tuple)) or \
+                isinstance(mo_occ[0], numpy.ndarray and mo_occ[0] == 2):
                 mo_occ = [mo for mo1 in mo_occ for mo in mo1]
         if mo_coeff is not None:
             skmoR, skmoI = _format_mo(mo_coeff, mo_occ, shape=(nset,nkpts), order='F',