diff --git a/vayesta/rpa/rirpa/RIdRRPA.py b/vayesta/rpa/rirpa/RIdRRPA.py
index 4866803b7..0aff47c7d 100644
--- a/vayesta/rpa/rirpa/RIdRRPA.py
+++ b/vayesta/rpa/rirpa/RIdRRPA.py
@@ -209,7 +209,7 @@ def kernel_energy(self, npoints=48, ainit=10, correction="linear"):
         # Note that eri contribution to A and B is equal, so can get trace over one by dividing by two
         e3 = 2 * (sum(self.eps) + np.tensordot(cderi, cderi, ((0, 1), (0, 1))))
         if cderi_neg is not None:
-             e3 -= np.tensordot(cderi_neg, cderi_neg, ((0, 1), (0, 1)))
+             e3 -= 2 * np.tensordot(cderi_neg, cderi_neg, ((0, 1), (0, 1)))
         err /= 2
         self.e_corr_ss = 0.5 * (e1 + e2 - e3)
         self.log.info(
diff --git a/vayesta/tests/rpa/test_rirpa_solids.py b/vayesta/tests/rpa/test_rirpa_solids.py
new file mode 100644
index 000000000..d82672a88
--- /dev/null
+++ b/vayesta/tests/rpa/test_rirpa_solids.py
@@ -0,0 +1,62 @@
+import pytest
+
+from vayesta import rpa
+from vayesta.tests.common import TestCase
+from vayesta.tests import testsystems
+
+
+class DiamondRIRPATest(TestCase):
+    PLACES = 8
+
+    @classmethod
+    def setUpClass(cls):
+        cls.sys = testsystems.diamond_sto3g_s211
+        cls.known_results = dict(e_tot=-149.51936410641733, e_corr=-0.19193623440986585)
+
+    def _test_energy(self, myrpa):
+        """Test the RPA energy.
+        """
+        self.assertAlmostEqual(myrpa.e_corr, self.known_results["e_corr"], self.PLACES)
+        self.assertAlmostEqual(myrpa.e_tot, self.known_results["e_tot"], self.PLACES)
+
+    @pytest.mark.slow
+    def test_energy_rhf_opt(self):
+        """Tests for diamond with optimised RHF dRPA code.
+        """
+
+        rirpa = rpa.rirpa.ssRIdRRPA(self.sys.rhf())
+        rirpa.kernel_energy()
+        self._test_energy(rirpa)
+
+    @pytest.mark.fast
+    def test_energy_rhf_generic(self):
+        """Tests for diamond with generic RHF RIRPA code.
+        """
+
+        rirpa = rpa.rirpa.ssRIRRPA(self.sys.rhf())
+        rirpa.kernel_energy()
+        self._test_energy(rirpa)
+
+    @pytest.mark.slow
+    def test_energy_uhf(self):
+        """Tests for diamond with generic UHF RIRPA code.
+        """
+
+        rirpa = rpa.rirpa.ssRIURPA(self.sys.uhf())
+        rirpa.kernel_energy()
+        self._test_energy(rirpa)
+
+    @pytest.mark.fast
+    def test_rhf_moments(self):
+        gen_rirpa = rpa.rirpa.ssRIRRPA(self.sys.rhf())
+        opt_rirpa = rpa.rirpa.ssRIdRRPA(self.sys.rhf())
+        mom0_gen = gen_rirpa.kernel_moms(0)[0]
+        mom0_opt = opt_rirpa.kernel_moms(0)[0]
+        self.assertAllclose(mom0_gen, mom0_opt, self.PLACES)
+
+@pytest.mark.slow
+class GrapheneRIRPATest(DiamondRIRPATest):
+    @classmethod
+    def setUpClass(cls):
+        cls.sys = testsystems.graphene_sto3g_s211
+        cls.known_results = dict(e_tot=-150.15057360171875, e_corr=-0.17724246753903117)
\ No newline at end of file
diff --git a/vayesta/tests/testsystems.py b/vayesta/tests/testsystems.py
index 34b6f14af..73c916267 100644
--- a/vayesta/tests/testsystems.py
+++ b/vayesta/tests/testsystems.py
@@ -446,6 +446,12 @@ def uhf(self):
 he_k321 = TestSolid(a, atom="He 0 0 0", basis="def2-svp", auxbasis="def2-svp-ri", kmesh=(3, 2, 1))
 he_s321 = TestSolid(a, atom="He 0 0 0", basis="def2-svp", auxbasis="def2-svp-ri", supercell=(3, 2, 1))
 
+a, atom = solids.graphene()
+opts = dict(basis='sto3g', auxbasis='sto3g', exp_to_discard=0.1, dimension=2)
+mesh = (2,1,1)
+graphene_sto3g_k211 = TestSolid(a=a, atom=atom, kmesh=mesh, **opts)
+graphene_sto3g_s211 = TestSolid(a=a, atom=atom, supercell=mesh, **opts)
+
 
 # Lattices