The error message "Fortran compiler cannot create executables" typically occurs during the installation of software packages, including Quantum Espresso, when there is an issue with the Fortran compiler configuration or availability. Fortran is a programming language commonly used in scientific and numerical computations.
Here are a few possible reasons for this error:
Fortran compiler not installed: The error can occur if a compatible Fortran compiler is not installed on your system. Quantum Espresso relies on a Fortran compiler to compile and create executables. Make sure you have a compatible Fortran compiler installed on your system.
Incorrect Fortran compiler configuration: Even if you have a Fortran compiler installed, the error can arise if the compiler's configuration is not set correctly. The installation process looks for the compiler in the default directories or in the paths specified during the installation. Verify that the compiler is correctly configured and accessible.
Missing or outdated dependencies: The error can also occur if certain dependencies required by the Fortran compiler are missing or outdated. Ensure that all the necessary dependencies, such as development libraries and runtime environments, are installed and up to date.
Incompatible compiler version: Quantum Espresso has specific requirements regarding the Fortran compiler version. If you are using an incompatible version, the installation might fail. Check the Quantum Espresso documentation or the installation instructions for the recommended Fortran compiler version.
Permissions or access issues: The error can occur if you do not have the necessary permissions to access the Fortran compiler or the directories where the compiler is installed. Ensure that you have the appropriate permissions to access and execute the compiler and related files.
To troubleshoot this issue, you can take the following steps:
- Check the Quantum Espresso documentation and installation instructions for specific compiler requirements and recommendations.
- Verify that a compatible Fortran compiler is installed on your system.
- Double-check the configuration of the Fortran compiler and ensure it is correctly set.
- Install any missing dependencies or update existing ones.
- If you are using a specific version of the compiler, ensure it is compatible with Quantum Espresso.
- Check the permissions and access rights for the compiler and related files.
If you encounter difficulties during the installation process, it is also helpful to consult the Quantum Espresso community or support channels for further assistance.