diff --git a/src/MC/fix_atom_swap.cpp b/src/MC/fix_atom_swap.cpp
index b66569be34..179ef852d9 100644
--- a/src/MC/fix_atom_swap.cpp
+++ b/src/MC/fix_atom_swap.cpp
@@ -56,7 +56,8 @@ using namespace MathConst;
 /* ---------------------------------------------------------------------- */
 
 FixAtomSwap::FixAtomSwap(LAMMPS *lmp, int narg, char **arg) :
-  Fix(lmp, narg, arg)
+  Fix(lmp, narg, arg),
+  idregion(NULL), type_list(NULL), mu(NULL), qtype(NULL), sqrt_mass_ratio(NULL), random_equal(NULL), random_unequal(NULL)
 {
   if (narg < 10) error->all(FLERR,"Illegal fix atom/swap command");
 
@@ -68,9 +69,7 @@ FixAtomSwap::FixAtomSwap(LAMMPS *lmp, int narg, char **arg) :
   extvector = 0;
   restart_global = 1;
   time_depend = 1;
-  type_list = NULL;
-  qtype = NULL;
-
+  
   // required args
 
   nevery = force->inumeric(FLERR,arg[3]);
diff --git a/src/MC/fix_bond_break.cpp b/src/MC/fix_bond_break.cpp
index 8e48f633e0..85d014defd 100755
--- a/src/MC/fix_bond_break.cpp
+++ b/src/MC/fix_bond_break.cpp
@@ -36,7 +36,8 @@ using namespace FixConst;
 /* ---------------------------------------------------------------------- */
 
 FixBondBreak::FixBondBreak(LAMMPS *lmp, int narg, char **arg) :
-  Fix(lmp, narg, arg)
+  Fix(lmp, narg, arg),
+  partner(NULL), finalpartner(NULL), distsq(NULL), broken(NULL), copy(NULL), random(NULL)
 {
   if (narg < 6) error->all(FLERR,"Illegal fix bond/break command");
 
@@ -98,11 +99,8 @@ FixBondBreak::FixBondBreak(LAMMPS *lmp, int narg, char **arg) :
   // allocate arrays local to this fix
 
   nmax = 0;
-  partner = finalpartner = NULL;
-  distsq = NULL;
 
   maxbreak = 0;
-  broken = NULL;
 
   // copy = special list for one atom
   // size = ms^2 + ms is sufficient
diff --git a/src/MC/fix_bond_create.cpp b/src/MC/fix_bond_create.cpp
index 6db8644cac..59e0e4cf75 100755
--- a/src/MC/fix_bond_create.cpp
+++ b/src/MC/fix_bond_create.cpp
@@ -39,7 +39,8 @@ using namespace FixConst;
 /* ---------------------------------------------------------------------- */
 
 FixBondCreate::FixBondCreate(LAMMPS *lmp, int narg, char **arg) :
-  Fix(lmp, narg, arg)
+  Fix(lmp, narg, arg),
+  bondcount(NULL), partner(NULL), finalpartner(NULL), distsq(NULL), created(NULL), copy(NULL), random(NULL)
 {
   if (narg < 8) error->all(FLERR,"Illegal fix bond/create command");
 
diff --git a/src/MC/fix_bond_swap.cpp b/src/MC/fix_bond_swap.cpp
index 31194ce12e..6d4cf8118b 100644
--- a/src/MC/fix_bond_swap.cpp
+++ b/src/MC/fix_bond_swap.cpp
@@ -52,7 +52,8 @@ static const char cite_fix_bond_swap[] =
 /* ---------------------------------------------------------------------- */
 
 FixBondSwap::FixBondSwap(LAMMPS *lmp, int narg, char **arg) :
-  Fix(lmp, narg, arg)
+  Fix(lmp, narg, arg),
+  tflag(0), alist(NULL), id_temp(NULL)
 {
   if (lmp->citeme) lmp->citeme->add(cite_fix_bond_swap);
 
diff --git a/src/MC/fix_gcmc.cpp b/src/MC/fix_gcmc.cpp
index aea029e5ba..ca93d7f993 100644
--- a/src/MC/fix_gcmc.cpp
+++ b/src/MC/fix_gcmc.cpp
@@ -58,7 +58,10 @@ enum{ATOM,MOLECULE};
 /* ---------------------------------------------------------------------- */
 
 FixGCMC::FixGCMC(LAMMPS *lmp, int narg, char **arg) :
-  Fix(lmp, narg, arg)
+  Fix(lmp, narg, arg),
+  idregion(NULL), full_flag(0), ngroups(0), groupstrings(NULL), ngrouptypes(0), grouptypestrings(NULL),
+  grouptypebits(NULL), grouptypes(NULL), local_gas_list(NULL), atom_coord(NULL), random_equal(NULL), random_unequal(NULL), 
+  coords(NULL), imageflags(NULL), idshake(NULL)
 {
   if (narg < 11) error->all(FLERR,"Illegal fix gcmc command");
 
diff --git a/src/MC/fix_tfmc.cpp b/src/MC/fix_tfmc.cpp
index 8ce1308694..cb9faaaf54 100755
--- a/src/MC/fix_tfmc.cpp
+++ b/src/MC/fix_tfmc.cpp
@@ -37,7 +37,8 @@ using namespace FixConst;
 /* ---------------------------------------------------------------------- */
 
 FixTFMC::FixTFMC(LAMMPS *lmp, int narg, char **arg) :
-  Fix(lmp, narg, arg)
+  Fix(lmp, narg, arg),
+  xd(NULL), rotflag(0)
 {
   if (narg < 6) error->all(FLERR,"Illegal fix tfmc command");