diff --git a/src/.gitignore b/src/.gitignore
index dab4225f44..d148466fce 100644
--- a/src/.gitignore
+++ b/src/.gitignore
@@ -115,10 +115,10 @@
 /fix_lambda_apip.h
 /fix_lambda_thermostat_apip.cpp
 /fix_lambda_thermostat_apip.h
-/pair_lambda_input.cpp
-/pair_lambda_input.h
-/pair_lambda_input_csp.cpp
-/pair_lambda_input_csp.h
+/pair_lambda_input_apip.cpp
+/pair_lambda_input_apip.h
+/pair_lambda_input_csp_apip.cpp
+/pair_lambda_input_csp_apip.h
 /pair_eam_fs_apip.cpp
 /pair_eam_fs_apip.h
 /pair_eam_apip.cpp
diff --git a/src/APIP/fix_atom_weight_apip.cpp b/src/APIP/fix_atom_weight_apip.cpp
index a9b99157d6..e06f983bfe 100644
--- a/src/APIP/fix_atom_weight_apip.cpp
+++ b/src/APIP/fix_atom_weight_apip.cpp
@@ -77,15 +77,15 @@ FixAtomWeightAPIP::FixAtomWeightAPIP(LAMMPS *lmp, int narg, char **arg) :
     avg_time_atom[1] = time_complex_atom;
   }
 
-  if (strcmp(arg[6], "lambda_input") == 0) {
-    time_group_extract_name = utils::strdup("lambda_input:time_per_atom");
+  if (strcmp(arg[6], "lambda/input") == 0) {
+    time_group_extract_name = utils::strdup("lambda/input/apip:time_per_atom");
   } else {
     time_group_atom = utils::numeric(FLERR, arg[6], false, lmp);
     avg_time_atom[2] = time_group_atom;
   }
 
   if (strcmp(arg[7], "lambda/zone") == 0) {
-    time_lambda_extract_name = utils::strdup("lambda_zone:time_per_atom");
+    time_lambda_extract_name = utils::strdup("lambda/zone/apip:time_per_atom");
   } else {
     time_lambda_atom = utils::numeric(FLERR, arg[7], false, lmp);
     avg_time_atom[3] = time_lambda_atom;
diff --git a/src/APIP/fix_lambda_apip.cpp b/src/APIP/fix_lambda_apip.cpp
index 2dac218707..8773a878a1 100644
--- a/src/APIP/fix_lambda_apip.cpp
+++ b/src/APIP/fix_lambda_apip.cpp
@@ -249,9 +249,9 @@ void FixLambdaAPIP::init()
 
   Pair *pair_tmp;
   // lambda_input
-  pair_tmp = force->pair_match("lambda_input/", 0);
+  pair_tmp = force->pair_match("lambda/input/", 0);
   if (!pair_tmp) error->all(FLERR, "fix lambda requires a `pair lambda_input`");
-  pair_lambda_input = (PairLambdaInput *) pair_tmp;
+  pair_lambda_input = (PairLambdaInputAPIP *) pair_tmp;
   // lambda/zone
   pair_tmp = force->pair_match("lambda/zone/apip", 1);
   if (!pair_tmp) error->all(FLERR, "fix lambda requires a `pair lambda`");
diff --git a/src/APIP/fix_lambda_apip.h b/src/APIP/fix_lambda_apip.h
index 074181acb7..985ca72613 100644
--- a/src/APIP/fix_lambda_apip.h
+++ b/src/APIP/fix_lambda_apip.h
@@ -24,13 +24,13 @@ FixStyle(lambda/apip,FixLambdaAPIP);
 #define LMP_FIX_LAMBDA_APIP_H
 
 #include "fix.h"
-#include "pair_lambda_input.h"
+#include "pair_lambda_input_apip.h"
 #include "pair_lambda_zone_apip.h"
 
 namespace LAMMPS_NS {
 
 class FixLambdaAPIP : public Fix {
-  friend class PairLambdaInput;
+  friend class PairLambdaInputAPIP;
   friend class PairLambdaZoneAPIP;
 
  public:
@@ -53,7 +53,7 @@ class FixLambdaAPIP : public Fix {
   enum { FORWARD_MAX, FORWARD_TA };
   int comm_forward_flag;    // flag that determines which variables are communicated in comm forward
 
-  class PairLambdaInput *pair_lambda_input;
+  class PairLambdaInputAPIP *pair_lambda_input;
   class PairLambdaZoneAPIP *pair_lambda_zone;
 
   double cut_lo;    ///< distance at which the cutoff function of the transition zone decays from 1
diff --git a/src/APIP/pair_lambda_input.cpp b/src/APIP/pair_lambda_input_apip.cpp
similarity index 88%
rename from src/APIP/pair_lambda_input.cpp
rename to src/APIP/pair_lambda_input_apip.cpp
index 112984120c..3eab8d6caa 100644
--- a/src/APIP/pair_lambda_input.cpp
+++ b/src/APIP/pair_lambda_input_apip.cpp
@@ -14,7 +14,7 @@
    Contributing author: David Immel (d.immel@fz-juelich.de, FZJ, Germany)
 ------------------------------------------------------------------------- */
 
-#include "pair_lambda_input.h"
+#include "pair_lambda_input_apip.h"
 
 #include "atom.h"
 #include "comm.h"
@@ -30,7 +30,7 @@ using namespace LAMMPS_NS;
 
 /* ---------------------------------------------------------------------- */
 
-PairLambdaInput::PairLambdaInput(LAMMPS *lmp) : Pair(lmp), fix_lambda(nullptr), cut(nullptr)
+PairLambdaInputAPIP::PairLambdaInputAPIP(LAMMPS *lmp) : Pair(lmp), fix_lambda(nullptr), cut(nullptr)
 {
 
   cut_global = -1;
@@ -42,7 +42,7 @@ PairLambdaInput::PairLambdaInput(LAMMPS *lmp) : Pair(lmp), fix_lambda(nullptr),
 
 /* ---------------------------------------------------------------------- */
 
-PairLambdaInput::~PairLambdaInput()
+PairLambdaInputAPIP::~PairLambdaInputAPIP()
 {
   if (copymode) return;
 
@@ -55,7 +55,7 @@ PairLambdaInput::~PairLambdaInput()
 }
 
 /* ---------------------------------------------------------------------- */
-void PairLambdaInput::coeff(int narg, char **arg)
+void PairLambdaInputAPIP::coeff(int narg, char **arg)
 {
   if (narg != 2) error->all(FLERR, "Incorrect args for pair coefficients");
   if (!allocated) allocate();
@@ -80,7 +80,7 @@ void PairLambdaInput::coeff(int narg, char **arg)
    allocate all arrays
 ------------------------------------------------------------------------- */
 
-void PairLambdaInput::allocate()
+void PairLambdaInputAPIP::allocate()
 {
   allocated = 1;
   int n = atom->ntypes + 1;
@@ -95,7 +95,7 @@ void PairLambdaInput::allocate()
 
 /* ---------------------------------------------------------------------- */
 
-void PairLambdaInput::compute(int eflag, int vflag)
+void PairLambdaInputAPIP::compute(int eflag, int vflag)
 {
   // basic stuff (see pair_zero)
   ev_init(eflag, vflag);
@@ -114,7 +114,7 @@ void PairLambdaInput::compute(int eflag, int vflag)
    global settings
 ------------------------------------------------------------------------- */
 
-void PairLambdaInput::settings(int narg, char **arg)
+void PairLambdaInputAPIP::settings(int narg, char **arg)
 {
   if (narg < 1) utils::missing_cmd_args(FLERR, "pair_style lambda_input", error);
 
@@ -133,7 +133,7 @@ void PairLambdaInput::settings(int narg, char **arg)
    init specific to this pair style
 ------------------------------------------------------------------------- */
 
-void PairLambdaInput::init_style()
+void PairLambdaInputAPIP::init_style()
 {
   if (!atom->apip_lambda_input_flag)
     error->all(FLERR, "pair_lambda input requires an atom style with lambda_input");
@@ -158,7 +158,7 @@ void PairLambdaInput::init_style()
    init for one type pair i,j and corresponding j,i
 ------------------------------------------------------------------------- */
 
-double PairLambdaInput::init_one(int i, int j)
+double PairLambdaInputAPIP::init_one(int i, int j)
 {
   if (setflag[i][j] == 0) { cut[i][j] = mix_distance(cut[i][i], cut[j][j]); }
   return cut[i][j];
@@ -170,7 +170,7 @@ double PairLambdaInput::init_one(int i, int j)
   * fix atom_weight/apip.
   */
 
-int PairLambdaInput::calculate_lambda_input()
+int PairLambdaInputAPIP::calculate_lambda_input()
 {
   int i, ii, inum;
   int *ilist;
@@ -193,7 +193,7 @@ int PairLambdaInput::calculate_lambda_input()
    set return values for timers and counted particles
 ------------------------------------------------------------------------- */
 
-void PairLambdaInput::calculate_time_per_atom()
+void PairLambdaInputAPIP::calculate_time_per_atom()
 {
   if (n_calculations > 0)
     time_per_atom = timer / n_calculations;
@@ -207,10 +207,10 @@ void PairLambdaInput::calculate_time_per_atom()
 
 /* ---------------------------------------------------------------------- */
 
-void *PairLambdaInput::extract(const char *str, int &dim)
+void *PairLambdaInputAPIP::extract(const char *str, int &dim)
 {
   dim = 0;
-  if (strcmp(str, "lambda_input:time_per_atom") == 0) {
+  if (strcmp(str, "lambda_input/apip:time_per_atom") == 0) {
     calculate_time_per_atom();
     return (void *) &time_per_atom;
   }
diff --git a/src/APIP/pair_lambda_input.h b/src/APIP/pair_lambda_input_apip.h
similarity index 88%
rename from src/APIP/pair_lambda_input.h
rename to src/APIP/pair_lambda_input_apip.h
index e6b38c8d6d..c218ed01c0 100644
--- a/src/APIP/pair_lambda_input.h
+++ b/src/APIP/pair_lambda_input_apip.h
@@ -16,24 +16,24 @@
 
 #ifdef PAIR_CLASS
 // clang-format off
-PairStyle(lambda_input,PairLambdaInput);
+PairStyle(lambda/input/apip,PairLambdaInputAPIP);
 // clang-format on
 #else
 
-#ifndef LMP_PAIR_LAMBDA_INPUT_H
-#define LMP_PAIR_LAMBDA_INPUT_H
+#ifndef LMP_PAIR_LAMBDA_INPUT_APIP_H
+#define LMP_PAIR_LAMBDA_INPUT_APIP_H
 
 #include "fix_lambda_apip.h"
 #include "pair.h"
 
 namespace LAMMPS_NS {
 
-class PairLambdaInput : public Pair {
+class PairLambdaInputAPIP : public Pair {
   friend class FixLambdaAPIP;
 
  public:
-  PairLambdaInput(class LAMMPS *);
-  ~PairLambdaInput() override;
+  PairLambdaInputAPIP(class LAMMPS *);
+  ~PairLambdaInputAPIP() override;
   void compute(int, int) override;
   virtual void settings(int, char **) override;
   void coeff(int, char **) override;
diff --git a/src/APIP/pair_lambda_input_csp.cpp b/src/APIP/pair_lambda_input_csp_apip.cpp
similarity index 94%
rename from src/APIP/pair_lambda_input_csp.cpp
rename to src/APIP/pair_lambda_input_csp_apip.cpp
index 82a4bd8986..5f921148b3 100644
--- a/src/APIP/pair_lambda_input_csp.cpp
+++ b/src/APIP/pair_lambda_input_csp_apip.cpp
@@ -14,7 +14,7 @@
    Contributing author: David Immel (d.immel@fz-juelich.de, FZJ, Germany)
 ------------------------------------------------------------------------- */
 
-#include "pair_lambda_input_csp.h"
+#include "pair_lambda_input_csp_apip.h"
 
 #include "atom.h"
 #include "error.h"
@@ -25,8 +25,8 @@ using namespace LAMMPS_NS;
 
 /* ---------------------------------------------------------------------- */
 
-PairLambdaInputCsp::PairLambdaInputCsp(LAMMPS *lmp) :
-    PairLambdaInput(lmp), distsq(nullptr), nearest(nullptr)
+PairLambdaInputCSPAPIP::PairLambdaInputCSPAPIP(LAMMPS *lmp) :
+    PairLambdaInputAPIP(lmp), distsq(nullptr), nearest(nullptr)
 {
   // set defaults
   nnn = 0;
@@ -37,7 +37,7 @@ PairLambdaInputCsp::PairLambdaInputCsp(LAMMPS *lmp) :
 
 /* ---------------------------------------------------------------------- */
 
-PairLambdaInputCsp::~PairLambdaInputCsp()
+PairLambdaInputCSPAPIP::~PairLambdaInputCSPAPIP()
 {
   if (copymode) return;
 
@@ -49,7 +49,7 @@ PairLambdaInputCsp::~PairLambdaInputCsp()
    global settings
 ------------------------------------------------------------------------- */
 
-void PairLambdaInputCsp::settings(int narg, char **arg)
+void PairLambdaInputCSPAPIP::settings(int narg, char **arg)
 {
   double cut_csp = 5;
 
@@ -103,7 +103,7 @@ void PairLambdaInputCsp::settings(int narg, char **arg)
   * fix atom_weight/apip.
   */
 
-int PairLambdaInputCsp::calculate_lambda_input()
+int PairLambdaInputCSPAPIP::calculate_lambda_input()
 {
   int i, j, k, ii, jj, kk, n, n_cutoff, inum, jnum;
   double xtmp, ytmp, ztmp, delx, dely, delz, rsq, value;
@@ -224,7 +224,7 @@ int PairLambdaInputCsp::calculate_lambda_input()
    2nd routine sorts auxiliary array at same time
 ------------------------------------------------------------------------- */
 
-void PairLambdaInputCsp::select(int k, int n, double *arr)
+void PairLambdaInputCSPAPIP::select(int k, int n, double *arr)
 {
   int i, ir, j, l, mid;
   double a;
@@ -263,7 +263,7 @@ void PairLambdaInputCsp::select(int k, int n, double *arr)
 
 /* ---------------------------------------------------------------------- */
 
-void PairLambdaInputCsp::select2(int k, int n, double *arr, int *iarr)
+void PairLambdaInputCSPAPIP::select2(int k, int n, double *arr, int *iarr)
 {
   int i, ir, j, l, mid, ia, itmp;
   double a;
diff --git a/src/APIP/pair_lambda_input_csp.h b/src/APIP/pair_lambda_input_csp_apip.h
similarity index 83%
rename from src/APIP/pair_lambda_input_csp.h
rename to src/APIP/pair_lambda_input_csp_apip.h
index 5dd8c5f50d..311c00ca7c 100644
--- a/src/APIP/pair_lambda_input_csp.h
+++ b/src/APIP/pair_lambda_input_csp_apip.h
@@ -16,22 +16,22 @@
 
 #ifdef PAIR_CLASS
 // clang-format off
-PairStyle(lambda_input/csp,PairLambdaInputCsp);
+PairStyle(lambda/input/csp/apip,PairLambdaInputCSPAPIP);
 // clang-format on
 #else
 
-#ifndef LMP_PAIR_LAMBDA_INPUT_CSP_H
-#define LMP_PAIR_LAMBDA_INPUT_CSP_H
+#ifndef LMP_PAIR_LAMBDA_INPUT_CSP_APIP_H
+#define LMP_PAIR_LAMBDA_INPUT_CSP_APIP_H
 
-#include "pair_lambda_input.h"
+#include "pair_lambda_input_apip.h"
 
 namespace LAMMPS_NS {
 
-class PairLambdaInputCsp : virtual public PairLambdaInput {
+class PairLambdaInputCSPAPIP : virtual public PairLambdaInputAPIP {
 
  public:
-  PairLambdaInputCsp(class LAMMPS *);
-  ~PairLambdaInputCsp();
+  PairLambdaInputCSPAPIP(class LAMMPS *);
+  ~PairLambdaInputCSPAPIP();
   void settings(int, char **) override;
 
  protected: