renamed cmake option

cmake/Modules/Packages/KSPACE.cmake

@@ -46,8 +46,8 @@ else()
   target_compile_definitions(lammps PRIVATE -DFFT_KISS)
 endif()
 
-option(LMP_HEFFTE  "Use heFFTe as the distributed FFT engine, overrides the FFT option."  OFF)
-if(LMP_HEFFTE)
+option(FFT_USE_HEFFTE  "Use heFFTe as the distributed FFT engine, overrides the FFT option."  OFF)
+if(FFT_USE_HEFFTE)
   # if FFT_HEFFTE is enabled, switch the builtin FFT engine with Heffte
   set(HEFFTE_BACKEND_VALUES FFTW MKL)
   set(HEFFTE_BACKEND "" CACHE STRING "Select heFFTe backend, e.g., FFTW or MKL")

doc/src/Build_settings.rst

@@ -59,7 +59,7 @@ better pipelining for packing and communication.
          -D FFT=value              # FFTW3 or MKL or KISS, default is FFTW3 if found, else KISS
          -D FFT_SINGLE=value       # yes or no (default), no = double precision
          -D FFT_PACK=value         # array (default) or pointer or memcpy
-         -D LMP_HEFFTE=value       # yes or no (default), yes links to heFFTe
+         -D FFT_USE_HEFFTE=value   # yes or no (default), yes links to heFFTe
 
       .. note::