Geant4 Installation on Mac

The easiest way to install Geant4 on Mac is to compile Geant4’s source code using CMake GUI, which can be installed using Homebrew:

brew install --cask cmake-app

Qt installed through brew install qt is version 6. Since version 11.4.0, Geant4 can be compiled with Qt 6 by default instead of 5. Because CMake can find Qt 6 installed through Homebrew automatically, no additional action is needed. However, for Geant4.11.3.x, I recommend Mac users to turn on GEANT4_USE_QT_QT6, which is off by default.

If you encounter any compilation error related to zlib or expat, enable GEANT4_USE_SYSTEM_EXPAT, and GEANT4_USE_SYSTEM_ZLIB. There is no need to install expat and zlib using Homebrew because they are already included in Xcode, which is automatically installed when you install Homebrew.