diff --git a/src/AMOEBA/amoeba_file.cpp b/src/AMOEBA/amoeba_file.cpp
index 6bf961cdab..0b707047bf 100644
--- a/src/AMOEBA/amoeba_file.cpp
+++ b/src/AMOEBA/amoeba_file.cpp
@@ -34,14 +34,14 @@ enum{MUTUAL,OPT,TCG,DIRECT};
 enum{NOFRAME,ZONLY,ZTHENX,BISECTOR,ZBISECT,THREEFOLD};
 enum{GEAR,ASPC,LSQR};
 
-#define MAXLINE 65536              // crazy big for TORSION-TORSION section
-#define MAX_TYPE_PER_GROUP 6       // max types per AMOEBA group
-#define MAX_FRAME_PER_TYPE 32      // max multipole frames for any AMOEBA type
+static constexpr int MAXLINE = 65536;             // crazy big for TORSION-TORSION section
+static constexpr int MAX_TYPE_PER_GROUP = 6;     // max types per AMOEBA group
+static constexpr int MAX_FRAME_PER_TYPE = 32;    // max multipole frames for any AMOEBA type
 
-#define DELTA_TYPE_CLASS 32
-#define DELTA_VDWL_PAIR 16
+static constexpr int DELTA_TYPE_CLASS = 32;
+static constexpr int DELTA_VDWL_PAIR = 16;
 
-#define BOHR 0.52917721067         // Bohr in Angstroms
+static constexpr double BOHR = 0.52917721067;    // Bohr in Angstroms
 
 // methods to read, parse, and store info from force field file
 
diff --git a/src/AMOEBA/fix_amoeba_bitorsion.cpp b/src/AMOEBA/fix_amoeba_bitorsion.cpp
index cb8c62819d..2a3618569f 100644
--- a/src/AMOEBA/fix_amoeba_bitorsion.cpp
+++ b/src/AMOEBA/fix_amoeba_bitorsion.cpp
@@ -32,10 +32,10 @@ using namespace LAMMPS_NS;
 using namespace FixConst;
 using namespace MathConst;
 
-#define BITORSIONMAX 6   // max # of BiTorsion terms stored by one atom
-#define LISTDELTA 10000
-#define LB_FACTOR 1.5
-#define MAXLINE 1024
+static constexpr int BITORSIONMAX = 6;   // max # of BiTorsion terms stored by one atom
+static constexpr int LISTDELTA = 10000;
+static constexpr double LB_FACTOR = 1.5;
+static constexpr int MAXLINE = 1024;
 
 // spline weighting factors
 
diff --git a/src/BOCS/fix_bocs.cpp b/src/BOCS/fix_bocs.cpp
index 4918f8d879..58da1430b0 100644
--- a/src/BOCS/fix_bocs.cpp
+++ b/src/BOCS/fix_bocs.cpp
@@ -55,14 +55,14 @@ static const char cite_user_bocs_package[] =
   "}\n\n";
 
 
-#define DELTAFLIP 0.1
-#define TILTMAX 1.5
 
 enum{NOBIAS,BIAS};
 enum{NONE,XYZ,XY,YZ,XZ};
 enum{ISO,ANISO,TRICLINIC};
 
-const int NUM_INPUT_DATA_COLUMNS = 2;     // columns in the pressure correction file
+static constexpr double DELTAFLIP = 0.1;
+static constexpr double TILTMAX = 1.5;
+static constexpr int NUM_INPUT_DATA_COLUMNS = 2;    // columns in the pressure correction file
 
 /* ----------------------------------------------------------------------
    NVT,NPH,NPT integrators for improved Nose-Hoover equations of motion
diff --git a/src/DPD-REACT/fix_eos_table.cpp b/src/DPD-REACT/fix_eos_table.cpp
index 36bbe4d478..9e17ab450e 100644
--- a/src/DPD-REACT/fix_eos_table.cpp
+++ b/src/DPD-REACT/fix_eos_table.cpp
@@ -24,7 +24,7 @@
 
 #include <cstring>
 
-#define MAXLINE 1024
+static constexpr int MAXLINE = 1024;
 
 using namespace LAMMPS_NS;
 using namespace FixConst;
diff --git a/src/DPD-REACT/fix_eos_table_rx.cpp b/src/DPD-REACT/fix_eos_table_rx.cpp
index f7afddc64f..24f57e399f 100644
--- a/src/DPD-REACT/fix_eos_table_rx.cpp
+++ b/src/DPD-REACT/fix_eos_table_rx.cpp
@@ -28,12 +28,12 @@
 #include <cmath>
 #include <cstring>
 
-#define MAXLINE 1024
+static constexpr int MAXLINE = 1024;
 
 #ifdef DBL_EPSILON
-  #define MY_EPSILON (10.0*DBL_EPSILON)
+static constexpr double MY_EPSILON = 10.0*DBL_EPSILON;
 #else
-  #define MY_EPSILON (10.0*2.220446049250313e-16)
+static constexpr double MY_EPSILON = 10.0*2.220446049250313e-16;
 #endif
 
 using namespace LAMMPS_NS;
diff --git a/src/DPD-REACT/fix_rx.cpp b/src/DPD-REACT/fix_rx.cpp
index cce88cf465..43ff5bfe0e 100644
--- a/src/DPD-REACT/fix_rx.cpp
+++ b/src/DPD-REACT/fix_rx.cpp
@@ -41,13 +41,13 @@ using namespace MathSpecial;
 enum{NONE,HARMONIC};
 enum{LUCY};
 
-#define MAXLINE 1024
-#define DELTA 4
+static constexpr int MAXLINE = 1024;
+static constexpr int DELTA = 4;
 
 #ifdef DBL_EPSILON
-  #define MY_EPSILON (10.0*DBL_EPSILON)
+static constexpr double MY_EPSILON = 10.0*DBL_EPSILON;
 #else
-  #define MY_EPSILON (10.0*2.220446049250313e-16)
+static constexpr double MY_EPSILON = 10.0*2.220446049250313e-16;
 #endif
 
 #define SparseKinetics_enableIntegralReactions (true)
diff --git a/src/DPD-REACT/pair_exp6_rx.cpp b/src/DPD-REACT/pair_exp6_rx.cpp
index c6b831f84b..d2294442ac 100644
--- a/src/DPD-REACT/pair_exp6_rx.cpp
+++ b/src/DPD-REACT/pair_exp6_rx.cpp
@@ -31,13 +31,13 @@
 using namespace LAMMPS_NS;
 using namespace MathSpecial;
 
-#define MAXLINE 1024
-#define DELTA 4
+static constexpr int MAXLINE = 1024;
+static constexpr int DELTA = 4;
 
 #ifdef DBL_EPSILON
-  #define MY_EPSILON (10.0*DBL_EPSILON)
+static constexpr double MY_EPSILON = 10.0*DBL_EPSILON;
 #else
-  #define MY_EPSILON (10.0*2.220446049250313e-16)
+static constexpr double MY_EPSILON = 10.0*2.220446049250313e-16;
 #endif
 
 #define oneFluidApproxParameter (-1)
diff --git a/src/DPD-REACT/pair_multi_lucy.cpp b/src/DPD-REACT/pair_multi_lucy.cpp
index 89263dd445..9810039c8f 100644
--- a/src/DPD-REACT/pair_multi_lucy.cpp
+++ b/src/DPD-REACT/pair_multi_lucy.cpp
@@ -41,7 +41,7 @@ using MathConst::MY_PI;
 
 enum{NONE,RLINEAR,RSQ};
 
-#define MAXLINE 1024
+static constexpr int MAXLINE = 1024;
 
 static const char cite_pair_multi_lucy[] =
   "pair_style multi/lucy command: doi:10.1063/1.4942520\n\n"
diff --git a/src/DPD-REACT/pair_multi_lucy_rx.cpp b/src/DPD-REACT/pair_multi_lucy_rx.cpp
index 9620908531..e0ce3f62fb 100644
--- a/src/DPD-REACT/pair_multi_lucy_rx.cpp
+++ b/src/DPD-REACT/pair_multi_lucy_rx.cpp
@@ -43,12 +43,12 @@ using MathConst::MY_PI;
 
 enum{NONE,RLINEAR,RSQ};
 
-#define MAXLINE 1024
+static constexpr int MAXLINE = 1024;
 
 #ifdef DBL_EPSILON
-  #define MY_EPSILON (10.0*DBL_EPSILON)
+static constexpr double MY_EPSILON = 10.0*DBL_EPSILON;
 #else
-  #define MY_EPSILON (10.0*2.220446049250313e-16)
+static constexpr double MY_EPSILON = 10.0*2.220446049250313e-16;
 #endif
 
 #define oneFluidParameter (-1)
diff --git a/src/INTEL/pair_snap_intel.cpp b/src/INTEL/pair_snap_intel.cpp
index d91f0adc36..7cf5e00dcc 100644
--- a/src/INTEL/pair_snap_intel.cpp
+++ b/src/INTEL/pair_snap_intel.cpp
@@ -34,8 +34,8 @@
 using namespace LAMMPS_NS;
 using namespace ip_simd;
 
-#define MAXLINE 1024
-#define MAXWORD 3
+static constexpr int MAXLINE = 1024;
+static constexpr int MAXWORD = 3;
 
 /* ---------------------------------------------------------------------- */
 
diff --git a/src/KIM/kim_interactions.cpp b/src/KIM/kim_interactions.cpp
index ce550bf5da..a8887ab275 100644
--- a/src/KIM/kim_interactions.cpp
+++ b/src/KIM/kim_interactions.cpp
@@ -81,7 +81,7 @@ extern "C" {
 
 using namespace LAMMPS_NS;
 
-#define MAXLINE 1024
+static constexpr int MAXLINE = 1024;
 
 /* ---------------------------------------------------------------------- */
 
diff --git a/src/KOKKOS/pair_exp6_rx_kokkos.cpp b/src/KOKKOS/pair_exp6_rx_kokkos.cpp
index b4576db89a..3d3d9bf27f 100644
--- a/src/KOKKOS/pair_exp6_rx_kokkos.cpp
+++ b/src/KOKKOS/pair_exp6_rx_kokkos.cpp
@@ -42,8 +42,8 @@
 using namespace LAMMPS_NS;
 using namespace MathSpecialKokkos;
 
-#define MAXLINE 1024
-#define DELTA 4
+static constexpr int MAXLINE = 1024;
+static constexpr int DELTA = 4;
 
 #ifdef DBL_EPSILON
   #define MY_EPSILON (10.0*DBL_EPSILON)
diff --git a/src/ML-IAP/mliap_descriptor_snap.cpp b/src/ML-IAP/mliap_descriptor_snap.cpp
index cec03fca76..1380c5c1ea 100644
--- a/src/ML-IAP/mliap_descriptor_snap.cpp
+++ b/src/ML-IAP/mliap_descriptor_snap.cpp
@@ -31,8 +31,8 @@
 
 using namespace LAMMPS_NS;
 
-#define MAXLINE 1024
-#define MAXWORD 3
+static constexpr int MAXLINE = 1024;
+static constexpr int MAXWORD = 3;
 
 /* ---------------------------------------------------------------------- */
 
diff --git a/src/ML-IAP/mliap_descriptor_so3.cpp b/src/ML-IAP/mliap_descriptor_so3.cpp
index 4f976f06be..59b54cfee7 100644
--- a/src/ML-IAP/mliap_descriptor_so3.cpp
+++ b/src/ML-IAP/mliap_descriptor_so3.cpp
@@ -30,8 +30,8 @@
 
 using namespace LAMMPS_NS;
 
-#define MAXLINE 1024
-#define MAXWORD 3
+static constexpr int MAXLINE = 1024;
+static constexpr int MAXWORD = 3;
 
 /* ---------------------------------------------------------------------- */
 
diff --git a/src/ML-IAP/mliap_model.cpp b/src/ML-IAP/mliap_model.cpp
index a93090d364..b23f02d343 100644
--- a/src/ML-IAP/mliap_model.cpp
+++ b/src/ML-IAP/mliap_model.cpp
@@ -26,8 +26,8 @@
 
 using namespace LAMMPS_NS;
 
-#define MAXLINE 1024
-#define MAXWORD 3
+static constexpr int MAXLINE = 1024;
+static constexpr int MAXWORD = 3;
 
 /* ---------------------------------------------------------------------- */
 
diff --git a/src/ML-IAP/mliap_model_nn.cpp b/src/ML-IAP/mliap_model_nn.cpp
index 6c039f9a07..685b0ce779 100644
--- a/src/ML-IAP/mliap_model_nn.cpp
+++ b/src/ML-IAP/mliap_model_nn.cpp
@@ -28,7 +28,7 @@
 
 using namespace LAMMPS_NS;
 
-#define MAXLINE 1024
+static constexpr int MAXLINE = 1024;
 
 /* ---------------------------------------------------------------------- */
 
diff --git a/src/ML-POD/fitpod_command.cpp b/src/ML-POD/fitpod_command.cpp
index 87de65c3e2..9ffb057173 100644
--- a/src/ML-POD/fitpod_command.cpp
+++ b/src/ML-POD/fitpod_command.cpp
@@ -33,8 +33,7 @@
 using namespace LAMMPS_NS;
 using MathSpecial::powint;
 
-#define MAXLINE 1024
-
+static constexpr int MAXLINE = 1024;
 static constexpr double SMALL = 1.0e-10;
 
 FitPOD::FitPOD(LAMMPS *_lmp) : Command(_lmp), podptr(nullptr)
diff --git a/src/ML-POD/mlpod.cpp b/src/ML-POD/mlpod.cpp
index f20498b50b..fba780bfae 100644
--- a/src/ML-POD/mlpod.cpp
+++ b/src/ML-POD/mlpod.cpp
@@ -35,7 +35,7 @@ using MathConst::MY_PI;
 using MathSpecial::cube;
 using MathSpecial::powint;
 
-#define MAXLINE 1024
+static constexpr int MAXLINE = 1024;
 
 MLPOD::podstruct::podstruct() :
     twobody{4, 8, 6}, threebody{4, 8, 5, 4}, fourbody{0, 0, 0, 0}, pbc(nullptr),
diff --git a/src/ML-RANN/pair_rann.cpp b/src/ML-RANN/pair_rann.cpp
index f2948cbb43..aa3578f2c9 100644
--- a/src/ML-RANN/pair_rann.cpp
+++ b/src/ML-RANN/pair_rann.cpp
@@ -55,7 +55,7 @@ DISTRIBUTION A. Approved for public release; distribution unlimited. OPSEC#4918
 #include "rann_fingerprint_radialscreenedspin.h"
 #include "rann_fingerprint_radialspin.h"
 
-#define MAXLINE 1024
+static constexpr int MAXLINE = 1024;
 
 using namespace LAMMPS_NS;
 
diff --git a/src/ML-SNAP/pair_snap.cpp b/src/ML-SNAP/pair_snap.cpp
index 3029e9212d..245ff4acc4 100644
--- a/src/ML-SNAP/pair_snap.cpp
+++ b/src/ML-SNAP/pair_snap.cpp
@@ -29,8 +29,8 @@
 
 using namespace LAMMPS_NS;
 
-#define MAXLINE 1024
-#define MAXWORD 3
+static constexpr int MAXLINE = 1024;
+static constexpr int MAXWORD = 3;
 
 /* ---------------------------------------------------------------------- */
 
diff --git a/src/PHONON/fix_phonon.cpp b/src/PHONON/fix_phonon.cpp
index 6b5294d308..7787cefd6e 100644
--- a/src/PHONON/fix_phonon.cpp
+++ b/src/PHONON/fix_phonon.cpp
@@ -45,7 +45,7 @@
 using namespace LAMMPS_NS;
 using namespace FixConst;
 
-#define MAXLINE 512
+static constexpr int MAXLINE = 512;
 
 enum{FORWARD=-1,BACKWARD=1};
 
diff --git a/src/REACTION/fix_bond_react.cpp b/src/REACTION/fix_bond_react.cpp
index 786f5bfe6e..e528ad30c7 100644
--- a/src/REACTION/fix_bond_react.cpp
+++ b/src/REACTION/fix_bond_react.cpp
@@ -77,11 +77,12 @@ static const char cite_fix_bond_react[] =
   " pages =   {9953--9961}\n"
   "}\n\n";
 
-#define BIG 1.0e20
-#define DELTA 16
-#define MAXGUESS 20 // max # of guesses allowed by superimpose algorithm
-#define MAXCONARGS 14 // max # of arguments for any type of constraint + rxnID
-#define NUMVARVALS 5 // max # of keyword values that have variables as input
+    "fix bond/react: reacter.org doi:10.1016/j.polymer.2017.09.038, "
+static constexpr double BIG = 1.0e20;
+static constexpr int DELTA = 16;
+static constexpr int MAXGUESS = 20;      // max # of guesses allowed by superimpose algorithm
+static constexpr int MAXCONARGS = 14;    // max # of arguments for any type of constraint + rxnID
+static constexpr int NUMVARVALS = 5;     // max # of keyword values that have variables as input
 
 // various statuses of superimpose algorithm:
 // ACCEPT: site successfully matched to pre-reacted template
diff --git a/src/REPLICA/neb.cpp b/src/REPLICA/neb.cpp
index 11933164eb..5ab2a14137 100644
--- a/src/REPLICA/neb.cpp
+++ b/src/REPLICA/neb.cpp
@@ -36,9 +36,9 @@
 using namespace LAMMPS_NS;
 using namespace MathConst;
 
-#define MAXLINE 256
-#define CHUNK 1024
-#define ATTRIBUTE_PERLINE 4
+static constexpr int MAXLINE = 256;
+static constexpr int CHUNK = 1024;
+static constexpr int ATTRIBUTE_PERLINE = 4;
 
 enum { DEFAULT, TERSE, VERBOSE };
 
diff --git a/src/SPIN/neb_spin.cpp b/src/SPIN/neb_spin.cpp
index e7ef9ff7ea..de680cd1e7 100644
--- a/src/SPIN/neb_spin.cpp
+++ b/src/SPIN/neb_spin.cpp
@@ -62,10 +62,11 @@ static const char cite_neb_spin[] =
   "doi={10.1016/j.cpc.2015.07.001}\n"
   "}\n\n";
 
-#define MAXLINE 256
-#define CHUNK 1024
+static constexpr int MAXLINE = 256;
+static constexpr int CHUNK = 1024;
+
 // 8 attributes: tag, spin norm, position (3), spin direction (3)
-#define ATTRIBUTE_PERLINE 8
+static constexpr int ATTRIBUTE_PERLINE = 8;
 
 /* ---------------------------------------------------------------------- */
 
diff --git a/src/angle_write.cpp b/src/angle_write.cpp
index fb0e65ccf5..62e780b32e 100644
--- a/src/angle_write.cpp
+++ b/src/angle_write.cpp
@@ -35,7 +35,7 @@ using MathConst::DEG2RAD;
 using MathConst::RAD2DEG;
 
 static constexpr double epsilon = 6.5e-6;
-#define MAXLINE 1024
+static constexpr int MAXLINE = 1024;
 /* ---------------------------------------------------------------------- */
 
 void AngleWrite::command(int narg, char **arg)
diff --git a/src/dihedral_write.cpp b/src/dihedral_write.cpp
index 3d87591bcc..ace1de309d 100644
--- a/src/dihedral_write.cpp
+++ b/src/dihedral_write.cpp
@@ -35,7 +35,7 @@ using MathConst::DEG2RAD;
 using MathConst::RAD2DEG;
 
 static constexpr double epsilon = 6.5e-6;
-#define MAXLINE 1024
+static constexpr int MAXLINE = 1024;
 /* ---------------------------------------------------------------------- */
 
 void DihedralWrite::command(int narg, char **arg)
diff --git a/src/molecule.cpp b/src/molecule.cpp
index f83d8658df..59f84154db 100644
--- a/src/molecule.cpp
+++ b/src/molecule.cpp
@@ -31,11 +31,11 @@
 
 using namespace LAMMPS_NS;
 
-#define MAXLINE 256
-#define EPSILON 1.0e-7
-#define BIG 1.0e20
+static constexpr int MAXLINE = 1024;
+static constexpr double EPSILON = 1.0e-7;
+static constexpr double BIG = 1.0e20;
 
-#define SINERTIA 0.4    // moment of inertia prefactor for sphere
+static constexpr double SINERTIA = 0.4;    // moment of inertia prefactor for sphere
 
 /* ---------------------------------------------------------------------- */
 
diff --git a/src/procmap.cpp b/src/procmap.cpp
index 6fcea50315..37f1fa3889 100644
--- a/src/procmap.cpp
+++ b/src/procmap.cpp
@@ -33,7 +33,7 @@
 
 using namespace LAMMPS_NS;
 
-#define MAXLINE 128
+static constexpr int MAXLINE = 128;
 
 /* ---------------------------------------------------------------------- */
 
diff --git a/src/universe.cpp b/src/universe.cpp
index e743816d92..69e96aaa9e 100644
--- a/src/universe.cpp
+++ b/src/universe.cpp
@@ -21,7 +21,7 @@
 
 using namespace LAMMPS_NS;
 
-#define MAXLINE 256
+static constexpr int MAXLINE = 256;
 
 /* ----------------------------------------------------------------------
    create & initialize the universe of processors in communicator