Example added for the dkh

examples/dkh/dkhscalar.py

@@ -0,0 +1,15 @@
+# Example to show how to perform the dkh scalar relativistic corrections in PySCF
+
+from pyscf import gto, scf
+from mrh.my_pyscf.dkh import dkh
+
+mol = gto.Mole(atom='''Ne 0 0 0''',basis='cc-pvdz-dk',verbose=3)
+
+# Scalar Relativisitc Effects
+# dkhord = 2 or 3 or 4
+# Default c(speed of light) used in PySCF is different from other softwares.
+
+mfdkh = scf.RHF(mol)
+mfdkh.get_hcore = lambda *args: dkh(mol,dkhord=2)
+mfdkh.kernel()
+