diff --git a/src/MAKE/OPTIONS/Makefile.intel_cpu b/src/MAKE/OPTIONS/Makefile.intel_cpu
index 41d0f959feeba082640a3da8aa883421ee786cdd..90dcb3f8fe1b44adbccc14990610d321ac2185b5 100644
--- a/src/MAKE/OPTIONS/Makefile.intel_cpu
+++ b/src/MAKE/OPTIONS/Makefile.intel_cpu
@@ -8,6 +8,7 @@ SHELL = /bin/sh
 
 CC =		mpiicpc 
 OPTFLAGS =      -xHost -O2 -fp-model fast=2 -no-prec-div -qoverride-limits
+                -qopt-zmm-usage=high
 CCFLAGS =	-qopenmp -qno-offload -fno-alias -ansi-alias -restrict \
                 -DLMP_INTEL_USELRT -DLMP_USE_MKL_RNG $(OPTFLAGS)
 SHFLAGS =	-fPIC
diff --git a/src/MAKE/OPTIONS/Makefile.intel_cpu_intelmpi b/src/MAKE/OPTIONS/Makefile.intel_cpu_intelmpi
index ef514f43c68f4401e62113cfc4c5ff34a7565175..144d28fae26ad644951c9b8d44eece883f9d3948 100644
--- a/src/MAKE/OPTIONS/Makefile.intel_cpu_intelmpi
+++ b/src/MAKE/OPTIONS/Makefile.intel_cpu_intelmpi
@@ -8,6 +8,7 @@ SHELL = /bin/sh
 
 CC =		mpiicpc 
 OPTFLAGS =      -xHost -O2 -fp-model fast=2 -no-prec-div -qoverride-limits
+                -qopt-zmm-usage=high
 CCFLAGS =	-qopenmp -qno-offload -fno-alias -ansi-alias -restrict \
                 -DLMP_INTEL_USELRT -DLMP_USE_MKL_RNG $(OPTFLAGS)
 SHFLAGS =	-fPIC
diff --git a/src/MAKE/OPTIONS/Makefile.intel_cpu_mpich b/src/MAKE/OPTIONS/Makefile.intel_cpu_mpich
index e4dc74d79b353d6984b7af74892a9455cbb79b37..102e66f8bb881971dd23904ac99716c8d78b4105 100644
--- a/src/MAKE/OPTIONS/Makefile.intel_cpu_mpich
+++ b/src/MAKE/OPTIONS/Makefile.intel_cpu_mpich
@@ -7,7 +7,8 @@ SHELL = /bin/sh
 # specify flags and libraries needed for your compiler
 
 CC =		mpicxx -cxx=icc
-OPTFLAGS =      -xHost -O2 -fp-model fast=2 -no-prec-div -qoverride-limits
+OPTFLAGS =      -xHost -O2 -fp-model fast=2 -no-prec-div -qoverride-limits \
+                -qopt-zmm-usage=high
 CCFLAGS =	-qopenmp -qno-offload -fno-alias -ansi-alias -restrict \
                 -DLMP_INTEL_USELRT -DLMP_USE_MKL_RNG $(OPTFLAGS)
 SHFLAGS =	-fPIC
diff --git a/src/MAKE/OPTIONS/Makefile.intel_cpu_openmpi b/src/MAKE/OPTIONS/Makefile.intel_cpu_openmpi
index 457a64b223a1fbd0c4859720ca939d3e99e96d5c..a0dea06aac499f5229c7781a2588681220996656 100644
--- a/src/MAKE/OPTIONS/Makefile.intel_cpu_openmpi
+++ b/src/MAKE/OPTIONS/Makefile.intel_cpu_openmpi
@@ -8,7 +8,8 @@ SHELL = /bin/sh
 
 export OMPI_CXX = icc
 CC =		mpicxx
-OPTFLAGS =      -xHost -O2 -fp-model fast=2 -no-prec-div -qoverride-limits
+OPTFLAGS =      -xHost -O2 -fp-model fast=2 -no-prec-div -qoverride-limits \
+                -qopt-zmm-usage=high
 CCFLAGS =	-qopenmp -qno-offload -fno-alias -ansi-alias -restrict \
                 -DLMP_INTEL_USELRT -DLMP_USE_MKL_RNG $(OPTFLAGS)
 SHFLAGS =	-fPIC
diff --git a/src/USER-INTEL/pair_tersoff_intel.cpp b/src/USER-INTEL/pair_tersoff_intel.cpp
index 9e0a888638b828c03a64648fe9dd0a7f3180387d..a59fe12f5ba0ffcd9ee96145f37337cd4231e21a 100644
--- a/src/USER-INTEL/pair_tersoff_intel.cpp
+++ b/src/USER-INTEL/pair_tersoff_intel.cpp
@@ -1372,7 +1372,7 @@ void IntelKernelTersoff<flt_t,acc_t,mic, pack_i>::attractive_vector(
   fvec vrij_hatx = vrijinv * vdijx;
   fvec vrij_haty = vrijinv * vdijy;
   fvec vrij_hatz = vrijinv * vdijz;
-  fvec rikinv = invsqrt(rsq2);
+  fvec rikinv = v::invsqrt(rsq2);
   fvec rik_hatx = rikinv * dikx;
   fvec rik_haty = rikinv * diky;
   fvec rik_hatz = rikinv * dikz;