ORCA CLI Options

This page documents the CLI options available for all ORCA jobs. Use chemsmart sub orca --help for the complete list.

Basic Command Structure

chemsmart sub [OPTIONS] orca [ORCA_OPTIONS] <SUBCMD> [SUBCMD_OPTIONS]

Tip

ORCA options are largely similar to Gaussian options with some ORCA-specific parameters.

ORCA Options

Project and File Options

Option	Type	Description
`-p, --project`	string	Project settings from `~/.chemsmart/orca/*.yaml`
`-f, --filename`	string	Input file for job preparation
`-l, --label`	string	Custom output filename (without extension)
`-a, --append-label`	string	String to append to the base filename
`-t, --title`	string	ORCA job title
`-i, --index`	string	Structure index (1-based, default: last structure)
`-P, --pubchem`	string	Query structure from PubChem

Note

-p uses the project name without the .yaml extension.
-f accepts various formats: .xyz, .com, .gjf, .log, .inp, or .out.

Molecular Properties Options

Option	Type	Description
`-c, --charge`	int	Molecular charge
`-m, --multiplicity`	int	Molecular multiplicity

Method and Basis Set Options

Option	Type	Description
`-A, --ab-initio`	string	Ab initio method (e.g., DLPNO-CCSD(T))
`-x, --functional`	string	DFT functional
`-D, --dispersion`	string	Dispersion correction
`-b, --basis`	string	Basis set
`-a, --aux-basis`	string	Auxiliary basis set
`-e, --extrapolation-basis`	string	Extrapolation basis set

SCF and Grid Options

Option	Type	Description
`-d, --defgrid`	choice	Grid: defgrid1, defgrid2, defgrid3 (default: defgrid2)
`--scf-tol`	choice	SCF tolerance: NormalSCF, LooseSCF, TightSCF, etc.
`--scf-algorithm`	choice	SCF algorithm: GDIIS, DIIS, SOSCF, AutoTRAH
`--scf-maxiter`	int	Maximum SCF iterations
`--scf-convergence`	float	SCF convergence criterion

Property Calculation Options

Option	Type	Description
`--dipole/--no-dipole`	bool	Dipole moment calculation
`--quadrupole/--no-quadrupole`	bool	Quadrupole moment calculation
`--forces/--no-forces`	bool	Forces calculation (default: disabled)

MDCI Options

Option	Type	Description
`--mdci-cutoff`	choice	MDCI cutoff: loose, normal, tight
`--mdci-density`	choice	MDCI density: none, unrelaxed, relaxed

Additional Options

Option	Type	Description
`-r, --additional-route-parameters`	string	Additional route parameters

Solvent Options

Solvent settings can be specified at the ORCA group level, which means they apply to any subcommand (sp, opt, ts, irc, scan, etc.). This is useful when the project settings define a gas-phase calculation but you want to add solvation for a particular run without modifying the project file.

They can also be specified at the subcommand level to override the group-level settings for a single calculation.

Option	Type	Description
`--remove-solvent/--no-remove-solvent`	bool	Remove solvent from the job, overriding project settings (default: disabled)
`-sm, --solvent-model`	string	Implicit solvent model: `cpcm` (CPCM with CPCM epsilon), `cpcmc` (CPCM with COSMO epsilon; replaces the legacy COSMO model removed in ORCA 4.0), `smd` (Minnesota SMD), or `cosmors` (openCOSMO-RS interface)
`-si, --solvent-id`	string	Named solvent identifier (e.g. `water`, `toluene`, `cyclohexane`). Omit when using a fully custom dielectric via `-so`
`-so, --solvent-options`	string	Additional parameters for the model’s solvent block (see tables below), newline-separated for multiple options
`-sf, --solventfilename`	path	Path to a solvent file for the `cosmors` model. Any file format is accepted — it does not have to be a `.cosmorsxyz` file. If the path points to a Gaussian output file (e.g. `basename.log`) or an ORCA output file (e.g. `basename.out`), chemsmart automatically converts it to `basename.cosmorsxyz` (via `Molecule.write_cosmorsxyz()`) before use. The `.cosmorsxyz` file is then copied to the running directory (scratch or job folder) and its basename (without the `.cosmorsxyz` extension) is written as `solventfilename "name"` inside the `%cosmors` block.

Note

For CPCM with a named solvent, CPCM(solvent_id) is written in the route line.
For CPCMC (CPCM + COSMO epsilon, replaces old COSMO keyword removed in ORCA 4.0), CPCMC(solvent_id) is written in the route line.
For SMD, SMD(solvent_id) is written in the route line (canonical ORCA 6.0 form). Any additional options (e.g. SurfaceType, SMD descriptors) go into the %cpcm block via -so.
For openCOSMO-RS (cosmors), COSMORS(solvent_id) is written in the route line and a %cosmors block is added with any -so parameters.

Warning

ORCA 6.1 duplicate-keyword guard (openCOSMO-RS only): ORCA raises an INPUT ERROR if COSMORS(solvent_id) is on the route line and solvent "solvent_id" also appears in the %cosmors block. When -si / solvent_id is set, chemsmart automatically filters out any solvent "..." lines from the %cosmors block to prevent this error. Note that solventfilename "..." is a different keyword (it specifies the path to a .cosmorsxyz file) and is not filtered.
For a custom dielectric (no named solvent), the bare keyword (CPCM, CPCMC, SMD, or COSMORS) is written in the route line and the dielectric constants go into the corresponding block via -so (or custom_solvent in the project YAML).
-so is only applied when a solvent model is active — it is ignored when --remove-solvent is used.

Supported %cpcm block options (via -so, for cpcm, cpcmc, and smd models):

Option	Description
`Epsilon <value>`	Static dielectric constant (used for custom/non-named solvents, e.g. `Epsilon 78.36`)
`Refrac <value>`	Refractive index (e.g. `Refrac 1.33`)
`SurfaceType <type>`	Cavity surface type: `gepol_ses`, `gepol_sas`, `vdw_gaussian` (default since ORCA 5), or `gepol_ses_gaussian`
`Rsolv <value>`	Solvent probe radius in Ångström (e.g. `Rsolv 1.30`)
`MaxIter <n>`	Maximum iterations (e.g. `MaxIter 100`)
`Tolerance <value>`	Convergence tolerance
`soln`, `soln25`, `sola`, `solb`, `solg`, `solc`, `solh`	SMD solvent descriptors (refractive index, H-bond acidity/basicity, surface tension, aromaticity, halogenicity); used only with the `smd` model

Supported %cosmors block options (via -so, for the cosmors model):

Note

The ORCA %cosmors keyword for temperature is temp (lowercase), as listed in the ORCA 6.0 manual.

Option	Description
`temp <value>`	Reference temperature in Kelvin (e.g. `temp 298.15`)
`aeff <value>`	Effective contact area between surface segments in Å² (default: `5.925`)
`lnalpha <value>`	Logarithm of the misfit prefactor (default: `0.202`)
`lnchb <value>`	Hydrogen bond (HB) strength parameter (default: `0.166`)
`chbt <value>`	Parameter for temperature dependence of HB (default: `1.50`)
`sigmahb <value>`	HB threshold parameter in e/Å² (default: `9.61e-3`)
`rav <value>`	Radius to average ideal screening charges in Å (default: `0.50`)
`fcorr <value>`	Parameter adjusted from dielectric screening energies (default: `2.40`)
`ravcorr <value>`	Additional radius for misfit energy calculation in Å (default: `1.00`)
`astd <value>`	Standard surface area normalization factor in Å² (default: `41.624`)
`zcoord <value>`	Coordination number (default: `10.0`)
`dgsolv_eta <value>`	Offset for solvation energy calculation (default: `-4.4480`)
`dgsolv_omegaring <value>`	Correction for solvation energy of molecules with rings (default: `0.2630`)
`dftfunc "name"`	DFT functional for COSMO-RS sub-calculations (default: `"BP86"`)
`dftbas "name"`	Basis set for COSMO-RS sub-calculations (default: `"def2-TZVPD"`)
`solvent "name"`	Solvent from the internal COSMO-RS database (e.g. `solvent "water"`)
`solventfilename "name"`	Name of the `.cosmorsxyz` solvent file to read (prefer the `-sf` CLI option, which also handles auto-conversion from `.log`/`.out` files)
`orbs_vac true\|false`	Reuse gas-phase orbitals for the conductor calculation (default: `false`)

Examples:

# CPCM with a named solvent (group-level, applies to all subcommands)
chemsmart sub orca -p myproject -f molecule.xyz -c 0 -m 1 -sm cpcm -si water sp

# CPCMC (CPCM + COSMO epsilon) with a named solvent
chemsmart sub orca -p myproject -f molecule.xyz -c 0 -m 1 -sm cpcmc -si water sp

# SMD with a named solvent (route: ! SMD(water))
chemsmart sub orca -p myproject -f molecule.xyz -c 0 -m 1 -sm smd -si water opt

# SMD with a surface-type option (goes into %cpcm block)
chemsmart sub orca -p myproject -f molecule.xyz -c 0 -m 1 -sm smd -si water -so 'SurfaceType gepol_ses' opt

# CPCMC with custom dielectric (no named solvent; replaces old COSMO usage)
chemsmart sub orca -p myproject -f molecule.xyz -c 0 -m 1 -sm cpcmc -so $'Epsilon 16.7\nRefrac 1.275' sp

# openCOSMO-RS with a named solvent and temperature (route: ! COSMORS(water))
chemsmart sub orca -p myproject -f molecule.xyz -c 0 -m 1 -sm cosmors -si water -so 'temp 298.15' sp

# openCOSMO-RS with a named solvent and a custom .cosmorsxyz file
chemsmart sub orca -p myproject -f molecule.xyz -c 0 -m 1 -sm cosmors -si water -sf /path/to/water.cosmorsxyz sp

# openCOSMO-RS with a named solvent and a Gaussian/ORCA output file (auto-converted to .cosmorsxyz)
chemsmart sub orca -p myproject -f molecule.xyz -c 0 -m 1 -sm cosmors -si water -sf /path/to/water.log sp
chemsmart sub orca -p myproject -f molecule.xyz -c 0 -m 1 -sm cosmors -si water -sf /path/to/water.out sp

# Custom dielectric (no named solvent): remove project solvent first, then set custom Epsilon/Refrac
chemsmart sub orca -p myproject -f molecule.xyz -c 0 -m 1 --remove-solvent sp -sm cpcm -so $'Epsilon 16.7\nRefrac 1.275'

# Subcommand-level override (overrides group-level solvent)
chemsmart sub orca -p myproject -f molecule.xyz -sm smd -si water sp -sm smd -si toluene

# Remove solvent defined in project settings
chemsmart sub orca -p solv_project -f molecule.xyz -c 0 -m 1 --remove-solvent sp

The SMD example produces:

! SMD(water) B3LYP def2-SVP ...

The SMD + SurfaceType example produces:

! SMD(water) B3LYP def2-SVP ...
%cpcm
  SurfaceType gepol_ses
end

The openCOSMO-RS example produces:

! COSMORS(water) B3LYP def2-SVP ...
%cosmors
  temp 298.15
end

The openCOSMO-RS with custom solvent file example produces (regardless of whether -sf points to a .cosmorsxyz, .log, or .out file — non-.cosmorsxyz files are auto-converted first):

! COSMORS(water) B3LYP def2-SVP ...
%cosmors
  solventfilename "water"
end

The custom-dielectric CPCM example produces:

! CPCM B3LYP def2-SVP ...
%cpcm
  Epsilon 16.7
  Refrac 1.275
end

Available Subcommands

Structure Optimization

Subcommand	Description
`opt`	Geometry optimization
`sp`	Single point calculation

Transition State Search

Subcommand	Description
`ts`	Transition state optimization
`modred`	Modified redundant coordinate optimization
`irc`	Intrinsic reaction coordinate calculations
`scan`	Coordinate scanning
`neb`	Nudged Elastic Band calculations

Direct Input

Subcommand	Description
`inp`	Run ORCA input file as-is

Next Steps

For detailed information on each job type: