Build system fixes

- re-enable UFF forcefield by setting correct lammps settings
- use FindPython instead of FindPython3

CMakeLists.txt

@@ -32,8 +32,8 @@ else()
 endif()
 
 # VIPSTER_PYLIB - add python bindings for library, default to OFF
-find_package(Python3 3.7 QUIET COMPONENTS Interpreter Development)
-cmake_dependent_option(VIPSTER_PYLIB "Standalone Python library" OFF ${Python3_FOUND} OFF)
+find_package(Python 3.7 QUIET COMPONENTS Interpreter Development)
+cmake_dependent_option(VIPSTER_PYLIB "Standalone Python library" OFF ${Python_FOUND} OFF)
 
 # VIPSTER_DESKTOP - add Qt-GUI target, default to ON if Qt available
 find_package(Qt6 CONFIG QUIET COMPONENTS Widgets Gui OpenGLWidgets)
@@ -48,7 +48,7 @@ if(tmp AND NOT ${VIPSTER_DESKTOP})
 endif()
 
 # VIPSTER_PYWIDGET - optional python widget for Qt GUI, default to ON if possible
-cmake_dependent_option(VIPSTER_PYWIDGET "Python shell in desktop app" ${Python3_FOUND} "VIPSTER_DESKTOP" OFF)
+cmake_dependent_option(VIPSTER_PYWIDGET "Python shell in desktop app" ${Python_FOUND} "VIPSTER_DESKTOP" OFF)
 
 # VIPSTER_LAMMPS - optional widget for interactive simulations, default to OFF
 cmake_dependent_option(VIPSTER_LAMMPS "Interactive LAMMPS in desktop app" OFF "VIPSTER_DESKTOP" OFF)

gui/qt/CMakeLists.txt

@@ -79,7 +79,7 @@ if(VIPSTER_PYWIDGET)
     FetchContent_MakeAvailable(pybind11)
     add_definitions(-DUSE_PYTHON)
     target_sources(vipster PRIVATE ${QTPY_SOURCES})
-    target_link_libraries(vipster PRIVATE bindings pybind11::embed Python3::Python)
+    target_link_libraries(vipster PRIVATE bindings pybind11::embed Python::Python)
 endif()
 
 # lammps-widget:
@@ -112,6 +112,7 @@ if(VIPSTER_LAMMPS)
         set(LAMMPS_EXCEPTIONS ON CACHE INTERNAL "")
         # enable simple and regularly used packages
         set(PKG_MOLECULE ON CACHE BOOL "")
+        set(PKG_EXTRA-MOLECULE ON CACHE BOOL "")
         set(PKG_MANYBODY ON CACHE BOOL "")
         set(PKG_RIGID ON CACHE BOOL "")
         set(PKG_KSPACE ON CACHE BOOL "")

python/CMakeLists.txt

@@ -32,7 +32,7 @@ if(VIPSTER_PYLIB)
 
     target_link_libraries(pyvipster PRIVATE bindings pybind11::module)
 
-    execute_process(COMMAND "${Python3_EXECUTABLE}" "-c"
+    execute_process(COMMAND "${Python_EXECUTABLE}" "-c"
 "import sysconfig as s; print(s.get_path('platlib'))"
         OUTPUT_VARIABLE PYTHON_SITE
         OUTPUT_STRIP_TRAILING_WHITESPACE)