Separated making Gonze's NAC force constants and showing resulting parameters

phonopy/api_phonopy.py

@@ -2888,8 +2888,8 @@ class Phonopy(object):
                     symprec=self._symprec)
             else:
                 if 'displacements' in self._displacement_dataset:
-                    msg = ("This data format of displacement_dataset is not "
-                           "usable unless fc_calculator is set.")
+                    msg = ("fc_calculator has to be set to produce force "
+                           "constans from this dataset.")
                     raise RuntimeError(msg)
                 self._force_constants = get_phonopy_fc2(
                     self._supercell,

phonopy/harmonic/dynamical_matrix.py

@@ -393,6 +393,7 @@ class DynamicalMatrixNAC(DynamicalMatrix):
             else:
                 self._G_cutoff = (3 * self._num_G_points / (4 * np.pi) /
                                   self._pcell.get_volume()) ** (1.0 / 3)
+            self._G_list = self._get_G_list(self._G_cutoff)
             if 'Lambda' in nac_params:
                 self._Lambda = nac_params['Lambda']
             else:
@@ -400,15 +401,7 @@ class DynamicalMatrixNAC(DynamicalMatrix):
                 GeG = self._G_cutoff ** 2 * np.trace(self._dielectric) / 3
                 self._Lambda = np.sqrt(- GeG / 4 / np.log(exp_cutoff))
 
-    def make_Gonze_nac_dataset(self, verbose=False):
-        self._G_list = self._get_G_list(self._G_cutoff)
-        if verbose:
-            print("NAC by Gonze et al., PRB 50, 13035(R) (1994), "
-                  "PRB 55, 10355 (1997):")
-            print("  G-cutoff distance: %5.2f" % self._G_cutoff)
-            print("  Number of G-points: %d" % len(self._G_list))
-            print("  Lambda: %6.2f" % self._Lambda)
-
+    def make_Gonze_nac_dataset(self):
         try:
             import phonopy._phonopy as phonoc
             self._set_c_dipole_dipole_q0()
@@ -420,6 +413,14 @@ class DynamicalMatrixNAC(DynamicalMatrix):
         self._set_Gonze_force_constants()
         self._Gonze_count = 0
 
+    def show_Gonze_nac_message(self):
+        print("Use NAC by Gonze et al (no real space sum in current "
+              "implementation)")
+        print("  PRB 50, 13035(R) (1994), PRB 55, 10355 (1997)")
+        print("  G-cutoff distance: %4.2f, Number of G-points: %d, "
+              "Lambda: %4.2f"
+              % (self._G_cutoff, len(self._G_list), self._Lambda))
+
     def run(self, q, q_direction=None):
         """Calculate dynamical matrix at q
 
@@ -447,7 +448,7 @@ class DynamicalMatrixNAC(DynamicalMatrix):
             self._set_Wang_dynamical_matrix(q, q_direction)
         else:
             if self._Gonze_force_constants is None:
-                self.make_Gonze_nac_dataset(self._log_level)
+                self.make_Gonze_nac_dataset()
             self._set_Gonze_dynamical_matrix(q, q_direction)
 
     def set_dynamical_matrix(self, q, q_direction=None):

scripts/phonopy

@@ -875,6 +875,11 @@ if settings.get_is_nac():
         if settings.get_nac_method() is not None:
             nac_params['method'] = settings.get_nac_method()
         phonon.nac_params = nac_params
+        if log_level > 0:
+            dm = phonon.dynamical_matrix
+            if (dm.is_nac() and dm.nac_method == 'gonze'):
+                dm.show_Gonze_nac_message()
+            print("")
 
         if log_level > 1:
             print("-" * 27 + " Dielectric constant " + "-" * 28)