remove debug code, move to toplevel dir and document kspace style zero

doc/src/Commands_kspace.rst

@@ -31,3 +31,5 @@ OPT.
    * :doc:`pppm/dielectric <kspace_style>`
    * :doc:`pppm/electrode (i) <kspace_style>`
    * :doc:`scafacos <kspace_style>`
+   * :doc:`zero <kspace_style>`
+

doc/src/Developer_plugins.rst

@@ -264,7 +264,7 @@ the plugin will override the existing code.  This can be used to modify
 the behavior of existing styles or to debug new versions of them without
 having to re-compile or re-install all of LAMMPS.
 
-.. versionupdated:: 12Jun2025
+.. versionchanged:: 12Jun2025
 
 When using the :doc:`clear <clear>` command, plugins are not unloaded
 but restored to their respective style maps.  This also applies when

doc/src/kspace_style.rst

@@ -32,6 +32,7 @@
 .. index:: kspace_style msm/cg/omp
 .. index:: kspace_style msm/dielectric
 .. index:: kspace_style scafacos
+.. index:: kspace_style zero
 
 kspace_style command
 ====================
@@ -43,7 +44,7 @@ Syntax
 
    kspace_style style value
 
-* style = *none* or *ewald* or *ewald/dipole* or *ewald/dipole/spin* or *ewald/disp* or *ewald/disp/dipole* or *ewald/omp* or *ewald/electrode* or *pppm* or *pppm/cg* or *pppm/disp* or *pppm/tip4p* or *pppm/stagger* or *pppm/disp/tip4p* or *pppm/gpu* or *pppm/intel* or *pppm/disp/intel* or *pppm/kk* or *pppm/omp* or *pppm/cg/omp* or *pppm/disp/tip4p/omp* or *pppm/tip4p/omp* or *pppm/dielectic* or *pppm/disp/dielectric* or *pppm/electrode* or *pppm/electrode/intel* or *msm* or *msm/cg* or *msm/omp* or *msm/cg/omp* or *msm/dielectric* or *scafacos*
+* style = *none* or *ewald* or *ewald/dipole* or *ewald/dipole/spin* or *ewald/disp* or *ewald/disp/dipole* or *ewald/omp* or *ewald/electrode* or *pppm* or *pppm/cg* or *pppm/disp* or *pppm/tip4p* or *pppm/stagger* or *pppm/disp/tip4p* or *pppm/gpu* or *pppm/intel* or *pppm/disp/intel* or *pppm/kk* or *pppm/omp* or *pppm/cg/omp* or *pppm/disp/tip4p/omp* or *pppm/tip4p/omp* or *pppm/dielectic* or *pppm/disp/dielectric* or *pppm/electrode* or *pppm/electrode/intel* or *msm* or *msm/cg* or *msm/omp* or *msm/cg/omp* or *msm/dielectric* or *scafacos* or *zero*
 
   .. parsed-literal::
 
@@ -121,6 +122,7 @@ Syntax
        *scafacos* values = method accuracy
          method = fmm or p2nfft or p3m or ewald or direct
          accuracy = desired relative error in forces
+       *zero* value = none
 
 Examples
 """"""""
@@ -132,6 +134,7 @@ Examples
    kspace_style msm 1.0e-4
    kspace_style scafacos fmm 1.0e-4
    kspace_style none
+   kspace_style zero
 
 Used in input scripts:
 
@@ -375,6 +378,13 @@ other ScaFaCoS options currently exposed to LAMMPS.
 
 ----------
 
+.. versionadded:: 12Jun2025
+
+The *zero* style does not do any calculations, but is compatible
+with all pair styles that require some version of a kspace style.
+
+----------
+
 The specified *accuracy* determines the relative RMS error in per-atom
 forces calculated by the long-range solver.  It is set as a
 dimensionless number, relative to the force that two unit point

examples/plugins/CMakeLists.txt

@@ -95,7 +95,6 @@ add_library(zero2plugin MODULE zero2plugin.cpp pair_zero2.cpp bond_zero2.cpp
 target_link_libraries(zero2plugin PRIVATE lammps)
 
 add_library(kspaceplugin MODULE kspaceplugin.cpp kspace_zero2.cpp)
-target_include_directories(kspaceplugin PRIVATE "${LAMMPS_HEADER_DIR}/KSPACE")
 target_link_libraries(kspaceplugin PRIVATE lammps)
 
 add_library(runminplugin MODULE runminplugin.cpp min_cg2.cpp verlet2.cpp)

examples/plugins/kspace_zero2.cpp

@@ -41,11 +41,6 @@ KSpaceZero2::KSpaceZero2(LAMMPS *lmp) : KSpace(lmp)
   spinflag = 1;
 }
 
-KSpaceZero2::~KSpaceZero2()
-{
-  fprintf(stderr, "In destructor for KSpace zero2. This = %p\n", this);
-}
-
 /* ---------------------------------------------------------------------- */
 
 void KSpaceZero2::settings(int narg, char **arg)

examples/plugins/kspace_zero2.h

@@ -21,7 +21,6 @@ namespace LAMMPS_NS {
 class KSpaceZero2 : public KSpace {
  public:
   KSpaceZero2(class LAMMPS *);
-  ~KSpaceZero2() override;
 
   void init() override;
   void setup() override;

examples/plugins/kspaceplugin.cpp

@@ -15,7 +15,6 @@ using namespace LAMMPS_NS;
 static KSpace *zero2creator(LAMMPS *lmp)
 {
   KSpace *ptr = (KSpace *) new KSpaceZero2(lmp);
-  fprintf(stderr, "Created zero2 instance at %p\n", ptr);
   return ptr;
 }
 

src/kspace_zero.cpp

@@ -41,11 +41,6 @@ KSpaceZero::KSpaceZero(LAMMPS *lmp) : KSpace(lmp)
   spinflag = 1;
 }
 
-KSpaceZero::~KSpaceZero()
-{
-  fprintf(stderr, "In destructor for KSpace zero. This = %p\n", this);
-}
-
 /* ---------------------------------------------------------------------- */
 
 void KSpaceZero::settings(int narg, char **arg)

src/kspace_zero.h

@@ -27,7 +27,6 @@ namespace LAMMPS_NS {
 class KSpaceZero : public KSpace {
  public:
   KSpaceZero(class LAMMPS *);
-  ~KSpaceZero() override;
 
   void init() override;
   void setup() override;