External tools
SilicoLab can launch without optional external tools. Install these programs only when you need the features that call them.
The built-in Hartree engine is the default for quantum chemistry. ORCA is an optional alternative for molecular single-point energies, geometry optimizations, and vibrational frequencies. Transition-state and periodic QM calculations currently use Hartree.
Install ORCA separately, then open Settings > Compute targets. In the ORCA row for This machine, enter the executable path and select Verify. SilicoLab deliberately does not search for ORCA or choose it automatically.
For ORCA inside WSL on Windows, set Command prefix to wsl.exe -e and set
Program to the executable’s Linux path, such as /opt/orca/orca. For a
native installation, leave the command prefix empty. Select ORCA explicitly in
the QM task panel or use qm energy --engine orca in a script.
ORCA starts with one CPU core. Requesting more cores enables ORCA’s %pal
parallel mode and requires mpirun to be available in the target environment.
Remote hosts have their own ORCA program setting. Enter a path valid on that host; a local path is never copied to a remote target.
GROMACS
Section titled “GROMACS”Molecular dynamics simulations require GROMACS to be installed separately.
GPU acceleration is strongly recommended. Running molecular dynamics on CPU alone is technically possible, but it is usually too slow for non-trivial systems.
- Windows: Install GROMACS inside
WSL with
sudo apt install gromacsfor a quick start. For GPU acceleration, compile GROMACS from source with CUDA inside WSL. - Linux: Install the package with
sudo apt install gromacsfor a quick start. For production MD, compile from source with CUDA or ROCm support. - macOS: Install with
brew install gromacs. GPU acceleration is not supported on Apple hardware, so MD performance will be limited.
After installation, open SilicoLab and let the engine settings detect the
gmx executable before running MD.
Remote hosts
Section titled “Remote hosts”Heavy calculations can also run on a remote Linux host over SSH. This is useful when your laptop has no GPU or when the required engine is available only on an HPC login node or workstation.
See Remote execution for the SSH setup flow.