diff --git a/doc/src/compute_fep.rst b/doc/src/compute_fep.rst
index 0832d6191a..279148a55d 100644
--- a/doc/src/compute_fep.rst
+++ b/doc/src/compute_fep.rst
@@ -163,7 +163,7 @@ the meaning of these parameters:
 +------------------------------------------------------------------------------+-------------------------+------------+
 | :doc:`born <pair_born>`                                                      | a,b,c                   | type pairs |
 +------------------------------------------------------------------------------+-------------------------+------------+
-| :doc:`buck <pair_buck>`                                                      | a,c                     | type pairs |
+| :doc:`buck, buck/coul/cut, buck/coul/long, buck/coul/msm  <pair_buck>`       | a,c                     | type pairs |
 +------------------------------------------------------------------------------+-------------------------+------------+
 | :doc:`buck/mdf <pair_mdf>`                                                   | a,c                     | type pairs |
 +------------------------------------------------------------------------------+-------------------------+------------+
diff --git a/doc/src/fix_adapt.rst b/doc/src/fix_adapt.rst
index 638895ecc9..aa34516d52 100644
--- a/doc/src/fix_adapt.rst
+++ b/doc/src/fix_adapt.rst
@@ -128,9 +128,9 @@ formulas for the meaning of these parameters:
 +------------------------------------------------------------------------------+--------------------------------------------------+-------------+
 | :doc:`born/coul/long, born/coul/msm <pair_born>`                             | coulombic_cutoff                                 | type global |
 +------------------------------------------------------------------------------+--------------------------------------------------+-------------+
-| :doc:`buck <pair_buck>`                                                      | a,c                                              | type pairs  |
+| :doc:`buck, buck/coul/cut  <pair_buck>`                                      | a,c                                              | type pairs  |
 +------------------------------------------------------------------------------+--------------------------------------------------+-------------+
-| :doc:`buck/coul/long, buck/coul/msm <pair_buck>`                             | coulombic_cutoff                                 | type global |
+| :doc:`buck/coul/long, buck/coul/msm <pair_buck>`                             | a,c,coulombic_cutoff                             | type pairs  |
 +------------------------------------------------------------------------------+--------------------------------------------------+-------------+
 | :doc:`buck/mdf <pair_mdf>`                                                   | a,c                                              | type pairs  |
 +------------------------------------------------------------------------------+--------------------------------------------------+-------------+
diff --git a/doc/src/fix_adapt_fep.rst b/doc/src/fix_adapt_fep.rst
index 0666d3965d..b45ac80429 100644
--- a/doc/src/fix_adapt_fep.rst
+++ b/doc/src/fix_adapt_fep.rst
@@ -120,7 +120,7 @@ styles and their energy formulas for the meaning of these parameters:
 +------------------------------------------------------------------------------+-------------------------+------------+
 | :doc:`born <pair_born>`                                                      | a,b,c                   | type pairs |
 +------------------------------------------------------------------------------+-------------------------+------------+
-| :doc:`buck <pair_buck>`                                                      | a,c                     | type pairs |
+| :doc:`buck, buck/coul/cut, buck/coul/long, buck/coul/msm  <pair_buck>`       | a,c                     | type pairs |
 +------------------------------------------------------------------------------+-------------------------+------------+
 | :doc:`buck/mdf <pair_mdf>`                                                   | a,c                     | type pairs |
 +------------------------------------------------------------------------------+-------------------------+------------+
diff --git a/src/KSPACE/pair_buck_coul_long.cpp b/src/KSPACE/pair_buck_coul_long.cpp
index 4a0b8a3a15..20202a8de2 100644
--- a/src/KSPACE/pair_buck_coul_long.cpp
+++ b/src/KSPACE/pair_buck_coul_long.cpp
@@ -558,5 +558,8 @@ void *PairBuckCoulLong::extract(const char *str, int &dim)
 {
   dim = 0;
   if (strcmp(str,"cut_coul") == 0) return (void *) &cut_coul;
+  dim = 2;
+  if (strcmp(str,"a") == 0) return (void *) a;
+  if (strcmp(str,"c") == 0) return (void *) c;
   return nullptr;
 }
diff --git a/src/KSPACE/pair_buck_coul_msm.cpp b/src/KSPACE/pair_buck_coul_msm.cpp
index 4c423a8afd..c7d237b161 100644
--- a/src/KSPACE/pair_buck_coul_msm.cpp
+++ b/src/KSPACE/pair_buck_coul_msm.cpp
@@ -246,5 +246,9 @@ void *PairBuckCoulMSM::extract(const char *str, int &dim)
 {
   dim = 0;
   if (strcmp(str,"cut_coul") == 0) return (void *) &cut_coul;
+  dim = 2;
+  if (strcmp(str,"a") == 0) return (void *) a;
+  if (strcmp(str,"c") == 0) return (void *) c;
+
   return nullptr;
 }
diff --git a/src/fix_nh.cpp b/src/fix_nh.cpp
index 46afe7b2d7..49a469d296 100644
--- a/src/fix_nh.cpp
+++ b/src/fix_nh.cpp
@@ -1754,13 +1754,13 @@ void *FixNH::extract(const char *str, int &dim)
   } else if (tstat_flag && strcmp(str,"mtchain") == 0) {
     return &mtchain;
   } else if (pstat_flag && strcmp(str,"mpchain") == 0) {
-    return &mtchain;
+    return &mpchain;
   }
   dim=1;
   if (tstat_flag && strcmp(str,"eta") == 0) {
     return &eta;
   } else if (pstat_flag && strcmp(str,"etap") == 0) {
-    return &eta;
+    return &etap;
   } else if (pstat_flag && strcmp(str,"p_flag") == 0) {
     return &p_flag;
   } else if (pstat_flag && strcmp(str,"p_start") == 0) {
diff --git a/src/pair_buck_coul_cut.cpp b/src/pair_buck_coul_cut.cpp
index 05b36d3620..bc95dfb6ab 100644
--- a/src/pair_buck_coul_cut.cpp
+++ b/src/pair_buck_coul_cut.cpp
@@ -470,3 +470,13 @@ double PairBuckCoulCut::single(int i, int j, int itype, int jtype,
   }
   return eng;
 }
+
+/* ---------------------------------------------------------------------- */
+
+void *PairBuckCoulCut::extract(const char *str, int &dim)
+{
+  dim = 2;
+  if (strcmp(str,"a") == 0) return (void *) a;
+  if (strcmp(str,"c") == 0) return (void *) c;
+  return nullptr;
+}
diff --git a/src/pair_buck_coul_cut.h b/src/pair_buck_coul_cut.h
index b400ca3152..fef8396335 100644
--- a/src/pair_buck_coul_cut.h
+++ b/src/pair_buck_coul_cut.h
@@ -40,6 +40,7 @@ class PairBuckCoulCut : public Pair {
   void write_data(FILE *);
   void write_data_all(FILE *);
   virtual double single(int, int, int, int, double, double, double, double &);
+  void *extract(const char *, int &);
 
  protected:
   double cut_lj_global,cut_coul_global;
diff --git a/unittest/force-styles/tests/mol-pair-buck_coul_cut.yaml b/unittest/force-styles/tests/mol-pair-buck_coul_cut.yaml
index 928473176d..da5850b91c 100644
--- a/unittest/force-styles/tests/mol-pair-buck_coul_cut.yaml
+++ b/unittest/force-styles/tests/mol-pair-buck_coul_cut.yaml
@@ -25,7 +25,9 @@ pair_coeff: ! |
   4 4 127198.698386798 0.207005479340455 37.2289658745028
   4 5 127198.698386798 0.207005479340455 37.2289658745028
   5 5 127198.698386798 0.207005479340455 37.2289658745028
-extract: ! ""
+extract: |
+  a 2
+  c 2
 natoms: 29
 init_vdwl: 143.749538808172
 init_coul: -127.494586297384
diff --git a/unittest/force-styles/tests/mol-pair-buck_coul_long.yaml b/unittest/force-styles/tests/mol-pair-buck_coul_long.yaml
index 07606715b8..c6271ab58e 100644
--- a/unittest/force-styles/tests/mol-pair-buck_coul_long.yaml
+++ b/unittest/force-styles/tests/mol-pair-buck_coul_long.yaml
@@ -30,7 +30,9 @@ pair_coeff: ! |
   4 4 127198.698386798 0.207005479340455 37.2289658745028
   4 5 127198.698386798 0.207005479340455 37.2289658745028
   5 5 127198.698386798 0.207005479340455 37.2289658745028
-extract: ! ""
+extract: |
+  a 2
+  c 2
 natoms: 29
 init_vdwl: 143.749538808172
 init_coul: 225.821815126925
diff --git a/unittest/force-styles/tests/mol-pair-buck_coul_msm.yaml b/unittest/force-styles/tests/mol-pair-buck_coul_msm.yaml
index ca38b6369d..41e91c6a9a 100644
--- a/unittest/force-styles/tests/mol-pair-buck_coul_msm.yaml
+++ b/unittest/force-styles/tests/mol-pair-buck_coul_msm.yaml
@@ -32,7 +32,9 @@ pair_coeff: ! |
   4 4 127198.698386798 0.207005479340455 37.2289658745028
   4 5 127198.698386798 0.207005479340455 37.2289658745028
   5 5 127198.698386798 0.207005479340455 37.2289658745028
-extract: ! ""
+extract: |
+  a 2
+  c 2
 natoms: 29
 init_vdwl: 143.749538808172
 init_coul: 226.465163473713
diff --git a/unittest/force-styles/tests/mol-pair-buck_coul_msm_table.yaml b/unittest/force-styles/tests/mol-pair-buck_coul_msm_table.yaml
index 24a23bb444..676aa0450a 100644
--- a/unittest/force-styles/tests/mol-pair-buck_coul_msm_table.yaml
+++ b/unittest/force-styles/tests/mol-pair-buck_coul_msm_table.yaml
@@ -32,7 +32,9 @@ pair_coeff: ! |
   4 4 127198.698386798 0.207005479340455 37.2289658745028
   4 5 127198.698386798 0.207005479340455 37.2289658745028
   5 5 127198.698386798 0.207005479340455 37.2289658745028
-extract: ! ""
+extract: |
+  a 2
+  c 2
 natoms: 29
 init_vdwl: 143.749538808172
 init_coul: 226.465163473713
diff --git a/unittest/force-styles/tests/mol-pair-buck_coul_table.yaml b/unittest/force-styles/tests/mol-pair-buck_coul_table.yaml
index 5e89b1ddf7..f56810d895 100644
--- a/unittest/force-styles/tests/mol-pair-buck_coul_table.yaml
+++ b/unittest/force-styles/tests/mol-pair-buck_coul_table.yaml
@@ -30,7 +30,9 @@ pair_coeff: ! |
   4 4 127198.698386798 0.207005479340455 37.2289658745028
   4 5 127198.698386798 0.207005479340455 37.2289658745028
   5 5 127198.698386798 0.207005479340455 37.2289658745028
-extract: ! ""
+extract: |
+  a 2
+  c 2
 natoms: 29
 init_vdwl: 143.749538808172
 init_coul: 225.821851347828