Supported compilers

GEOS-Chem is written in the Fortran programming language. However, you will also need C and C++ compilers to install certain libraries (like netCDF) on your system.

Intel

The Intel Compiler Suite is our recommended proprietary compiler suite.

Intel compilers produce well-optimized code that runs extremely efficiency on machines with Intel CPUs. Many universities and institutions will have an Intel site license that allows you to use these compilers.

The GCST has tested GEOS-Chem Classic with these versions (but others may work as well):

  • 23.0.0

  • 19.0.5.281

  • 19.0.4

Older compiler versions than these may either be incompatible with GEOS-Chem, or may cause unexpected results. We hope to be able to port GEOS-Chem to the latest Intel 2024 compiler suite (icx for C, C++ and ifx for Fortran) in the near future.

Best way to install: Direct from Intel (Older versions may require purchase of a site license or a student license)

Tip

Intel 2021 and later may be obtained for free, or installed with a package manager such as Spack.

GNU

The GNU Compiler Collection (or GCC for short) is our recommended open-source compiler suite.

Because the GNU Compiler Collection is free and open source, this is a good choice if your institution lacks an Intel site license, or if you are running GEOS-Chem on the Amazon EC2 cloud environment.

The GCST has tested GEOS-Chem Classic with these versions (but others may work as well):

  • 12.2.0

  • 11.2.0

  • 11.1.0

  • 10.2.0

  • 9.3.0

  • 9.2.0

  • 8.2.0

  • 7.4.0

  • 7.3.0

  • 7.1.0

  • 6.2.0

We recommend using GCC 10 or later if possible. We have not thoroughly tested GEOS-Chem with compiler versions more recent than GCC 12 as of January 2025.

Best way to install: With Spack.

Other compilers

We currently have no plans to port GEOS-Chem to compilers other than Intel and GNU. But when we interface GEOS-Chem into external models (such as CESM); all compilers used by the parent model can successfully parse GEOS-Chem source code.