From 561697246048f1762c6525649b8484b288475ebc Mon Sep 17 00:00:00 2001
From: fishjojo <zhangxing.nju@gmail.com>
Date: Sun, 5 Feb 2023 19:48:51 -0800
Subject: [PATCH] fix k-point symmetry adapted KS-DFT with Newton solver (issue
 #1462)

---
 pyscf/pbc/dft/numint.py              |  7 +++++++
 pyscf/pbc/dft/test/test_krks_ksym.py | 14 ++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/pyscf/pbc/dft/numint.py b/pyscf/pbc/dft/numint.py
index a8ca103c28..74ba8349fe 100644
--- a/pyscf/pbc/dft/numint.py
+++ b/pyscf/pbc/dft/numint.py
@@ -27,6 +27,7 @@
 from pyscf.dft.gen_grid import NBINS, CUTOFF, ALIGNMENT_UNIT
 from pyscf.pbc.dft.gen_grid import make_mask, BLKSIZE
 from pyscf.pbc.lib.kpts_helper import member, is_zero
+from pyscf.pbc.lib.kpts import KPoints
 
 
 def eval_ao(cell, coords, kpt=numpy.zeros(3), deriv=0, relativity=0, shls_slice=None,
@@ -554,6 +555,8 @@ def nr_rks_fxc(ni, cell, grids, xc_code, dm0, dms, relativity=0, hermi=0,
     '''
     if kpts is None:
         kpts = numpy.zeros((1,3))
+    if isinstance(kpts, KPoints):
+        kpts = kpts.kpts_ibz
     xctype = ni._xc_type(xc_code)
     if xctype == 'LDA':
         ao_deriv = 0
@@ -843,6 +846,10 @@ def cache_xc_kernel(ni, cell, grids, xc_code, mo_coeff, mo_occ, spin=0,
     '''
     if kpts is None:
         kpts = numpy.zeros((1,3))
+    if isinstance(kpts, KPoints):
+        mo_coeff = kpts.transform_mo_coeff(mo_coeff)
+        mo_occ = kpts.transform_mo_occ(mo_occ)
+        kpts = kpts.kpts
     xctype = ni._xc_type(xc_code)
     if xctype == 'GGA':
         ao_deriv = 1
diff --git a/pyscf/pbc/dft/test/test_krks_ksym.py b/pyscf/pbc/dft/test/test_krks_ksym.py
index caa5db1573..f55e78a43b 100644
--- a/pyscf/pbc/dft/test/test_krks_ksym.py
+++ b/pyscf/pbc/dft/test/test_krks_ksym.py
@@ -152,6 +152,20 @@ def test_gga_df(self):
         kmf.kernel()
         self.assertAlmostEqual(kmf.e_tot, kmf0.e_tot, 9)
 
+    def test_gga_df_newton(self):
+        kpts0 = He.make_kpts(nk, with_gamma_point=False)
+        kmf0 = krks.KRKS(He, kpts=kpts0).density_fit()
+        kmf0.xc = 'pbe'
+        kmf0 = kmf0.newton()
+        kmf0.kernel()
+
+        kpts = He.make_kpts(nk, with_gamma_point=False, space_group_symmetry=True,time_reversal_symmetry=True)
+        kmf = pscf.KRKS(He, kpts=kpts).density_fit()
+        kmf.xc = 'pbe'
+        kmf = kmf.newton()
+        kmf.kernel()
+        self.assertAlmostEqual(kmf.e_tot, kmf0.e_tot, 9)
+
     def test_rsh_df(self):
         kpts0 = He.make_kpts(nk, with_gamma_point=False)
         kmf0 = krks.KRKS(He, kpts=kpts0).density_fit()