Merge pull request #4868 from camelto2/nxs_soc_jastrow_cusp

Nexus: set correct cusp in SOC jastrow
QMCPACK · Dec 9, 2023 · e818f01 · e818f01
2 parents f625e0a + 9185efb
commit e818f01
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Showing 3 changed files with 9 additions and 2 deletions.
diff --git a/docs/spin_orbit.rst b/docs/spin_orbit.rst
@@ -75,7 +75,7 @@ where we now utilize determinants of spinors, as opposed to the usual product of
           </correlation>
        </jastrow> 
       <jastrow type="Two-Body" name="J2" function="bspline" print="yes">
-        <correlation speciesA="u" speciesB="u" size="8">
+        <correlation speciesA="u" speciesB="u" size="8" cusp="-0.5">
           <coefficients id="uu" type="Array">                  
           </coefficients>
         </correlation> 
@@ -88,8 +88,9 @@ need a product of up and down determinants.
 In the Jastrow specification, we only need to provide 
 the jastrow terms for the same spin as there is no longer a
 distinction between the up and down spins. 
+The electon-electron cusp in this case should be -1/2, as discussed in :cite:`Melton2016-2`.
 
-We also make a small modification in the particleset specification:
+We also make a small modification in the particleset specification 
 
 .. code-block::
   :caption: specification for the electron particle when performing spin-orbit calculations

diff --git a/nexus/lib/qmcpack.py b/nexus/lib/qmcpack.py
@@ -287,11 +287,14 @@ def incorporate_result(self,result_name,result,sim):
                 spinor = input.get('spinor')
                 if spinor is not None and spinor:
                     # remove u-d term from optmized jastrow
+                    # also set correct cusp condition
                     J2 = optwf.get('J2')
                     if J2 is not None:
                         corr = J2.get('correlation')
                         if 'ud' in corr:
                             del corr.ud
+                        if 'uu' in corr:
+                            corr.uu.cusp = -0.5
                         #end if
                     #end if
                 #end if

diff --git a/nexus/lib/qmcpack_input.py b/nexus/lib/qmcpack_input.py
@@ -7609,11 +7609,14 @@ def generate_basic_input(**kwargs):
 
     if kw.spinor is not None and kw.spinor:
       # remove u-d 
+      # also set correct cusp
       J2 = wfn.jastrows.get('J2')
       if J2 is not None:
         corr = J2.get('correlation')
         if 'ud' in corr:
           del corr.ud
+        if 'uu' in corr:
+          corr.uu.cusp = -0.5
 
     h_estimators = kw.estimators
     d_estimators = None