Advanced ORCA Calculation

Goal

Enable advanced ORCA quantum chemistry calculations by constructing a custom ORCA input file from scratch. This skill covers methods and features not available through the SCINE wrapper, including multi-reference methods, excited states, relativistic effects, advanced SCF settings, NMR/EPR properties, and more.

[!IMPORTANT] For standard DFT single-point calculations (energy, gradients, Hessian), use the singlepoint skill instead. For geometry optimization, use the optimization skill. This skill is for cases where those wrappers do not expose the needed method or settings.

1. Prerequisites

• Conda environment: orca-agent with ase installed (SCINE not required for this skill)
• ORCA binary: The environment variable ORCA_BINARY_PATH must point to the ORCA executable

  export ORCA_BINARY_PATH=/path/to/orca
  

• ORCA documentation: Consult the ORCA 6.1 tutorials for method-specific input syntax, keyword blocks, and recommended settings

2. Workflow