Getting Started

Installation

The ORCA step is installed with the SEAMM Manager, and is probably already part of your SEAMM installation. To add it, or bring it up to date:

seamm-manager install orca-step
seamm-manager update orca-step

or use the Manager’s window. ORCA itself is licensed software that you install yourself, so installing the step does not install ORCA. Instead it creates ~/SEAMM/orca.ini – or orca.ini in whichever SEAMM installation you are working on – which tells SEAMM where ORCA is and how to run it. An existing file is never changed.

If code is not given in orca.ini, SEAMM runs the orca on your PATH, using its full path as ORCA requires.

A first calculation

Add an ORCA step to your flowchart and open it to reveal the ORCA sub-flowchart, then add an Energy (or Optimization) sub-step. In that sub-step either leave Use the global model chemistry on (to take the method and basis from a preceding Model Chemistry step) or turn it off and choose them directly — for example set Method to DFT, Functional type to global hybrid, Functional to B3LYP, and the basis to def2-TZVP. On the Results tab, tick the energy (and gradients if you want forces) to save them. Run the flowchart as usual.

To run ORCA in parallel, set ncores in the [orca-step] section of the main SEAMM configuration (~/.seamm.d/seamm.ini); the path to ORCA and, for parallel runs, the OpenMPI library-path go in ~/SEAMM/orca.ini (see the User Guide).

That should be enough to get started. For more detail about the functionality in this plug-in, see the User Guide.