Namespaces
namespace	impl

Classes
struct	AccelerationPlan

struct	AssignedEnergy

class	CEModelCrystalGrowthCalculator

struct	CGConfig

struct	CGPreparation
	Result of loading and configuring a cg run: the crystal, the calculator options and any per-molecule charges. More...

class	CGSolvationModel
	Produces solvation surfaces for the cg pipeline. More...

struct	CGSolvationResult
	Per-monomer solvation surfaces, plus the wavefunctions the model can offer for solution-phase monomer and interaction energies. More...

struct	CGSolvationSettings
	Settings the concrete models need; a superset, each uses what applies. More...

struct	ConductorResult

struct	ConductorSettings
	Settings for the ideal-conductor COSMO calculation the segment descriptors are built from. More...

struct	CorrelationOptions
	Options for a post-HF correlation calculation on a converged SCF wavefunction. More...

struct	CorrelationResult
	Result of a post-HF correlation calculation. More...

struct	CosmoRSSettings

struct	CosmoRSSolvation
	A solvation free energy and the intermediates worth keeping. More...

struct	CosmoRSSolvationSettings
	Settings for a single-molecule openCOSMO-RS solvation free energy. More...

class	CrystalGrowthCalculator

struct	CrystalGrowthCalculatorOptions

struct	CrystalSurfaceEnergies

struct	DMAConfig

class	DMADriver

struct	DMAReferenceLevel
	Reference QM level for the monomer multipoles in the DMA+exp-6 model. More...

class	DummyCrystalGrowthCalculator

struct	FacetEnergies

struct	MethodSpec

struct	MorphologyOptions
	Options for the particle size/shape-dependent energy calculation. More...

struct	SolventSpec
	A solvent, possibly a mixture, at a temperature. More...

struct	VibrationalAnalysisConfig
	Configuration options for vibrational frequency analysis. More...

class	XTBCrystalGrowthCalculator

Typedefs
using	WavefunctionList = std::vector< Wavefunction >

using	MoleculeList = std::vector< occ::core::Molecule >

Enumerations
enum class	SolvationModelKind { None , Smd , CosmoRS }

enum class	WavefunctionChoice { GasPhase , Solvated }

enum class	MethodKind { HF , DFT , MP2 , CCSD , CCSD_T , GFN2 }

Functions
std::size_t	df_exchange_memory_budget ()
	Decide SCF acceleration (density fitting / COSX) for a calculation.

std::size_t	df_exchange_intermediate_bytes (std::size_t nocc, std::size_t nbf, std::size_t ndf)
	Bytes DF-K would need for its half-transformed intermediate.

AccelerationPlan	plan_acceleration (io::RIPolicy policy, const std::string &orbital_basis_name, std::size_t nbf, double exact_exchange, const std::string &user_df_basis, bool user_cosx, std::size_t df_exchange_bytes=0)

template<typename Proc >
void	apply_acceleration (Proc &proc, std::size_t nbf, const io::OccInput &config, bool allow_cosx=true)
	Apply the active acceleration policy (DF / COSX) to an SCF procedure.

CGPreparation	prepare_cg (CGConfig const &config)
	Load the crystal and build calculator options + charges from `config`.

occ::cg::CrystalGrowthResult	run_cg_pipeline (CrystalGrowthCalculator &calc, const CrystalGrowthCalculatorOptions &opts, CGConfig const &config)
	Run the full crystal-growth pipeline on an already-constructed calculator: monomer energies -> lattice convergence -> molecular surroundings -> surface energies / morphology -> JSON serialization.

occ::cg::CrystalGrowthResult	run_cg (CGConfig const &)

SolvationModelKind	parse_solvation_model (const std::string &)

std::string	solvation_model_name (SolvationModelKind)

std::unique_ptr< CGSolvationModel >	make_cg_solvation_model (SolvationModelKind kind, const CGSolvationSettings &settings)

CorrelationResult	run_correlation (const qm::Wavefunction &wfn, const CorrelationOptions &opts={})
	Run an MP2 / CCSD / CCSD(T) calculation on a converged SCF wavefunction, with the same backend dispatch, auxiliary-basis resolution and frozen-core handling as the CLI.

solvent::cosmors::Segments	conductor_segments (const qm::Wavefunction &wavefunction, const solvent::cosmors::Parameters &params={}, double probe_radius_angs=0.0, int angular_points=590, bool constrain_charge=true, Vec dielectric_energies=nullptr, double cavity_volume_angs3=nullptr)
	Build segments from a wavefunction that has already been converged in the ideal-conductor reaction field, with both σ and σ⊥ averaged on `params`.

ConductorResult	conductor_profile (const qm::Wavefunction &gas_wavefunction, const ConductorSettings &settings={})
	Converge the SCF in the ideal-conductor reaction field starting from a gas-phase wavefunction, then build the segments.

CosmoRSSolvation	cosmors_solvation_free_energy (const core::Molecule &solute, const std::string &solvent_name, const CosmoRSSolvationSettings &settings={})
	Solvation free energy of `solute` in a named solvent, end to end.

CosmoRSSolvation	cosmors_solvation_free_energy (const core::Molecule &solute, const core::Molecule &solvent, const CosmoRSSolvationSettings &settings={})
	The same, computing the solvent's conductor cavity from its geometry instead of loading a cached ensemble.

std::vector< std::string >	available_cosmors_solvents ()
	Solvent names with a cached segment ensemble, sorted.

CGSolvationResult	cosmors_solvation (const std::string &basename, const std::vector< core::Molecule > &molecules, const std::vector< qm::Wavefunction > &gas_wavefunctions, const SolventSpec &solvent, const CosmoRSSettings &settings={})
	Build openCOSMO-RS solvation surfaces for each molecule in `solvent`.

std::vector< AssignedEnergy >	assign_interaction_terms_to_nearest_neighbours (const crystal::CrystalDimers::MoleculeNeighbors &neighbors, const std::vector< double > &dimer_energies, double cg_radius)

MorphologyResult	compute_crystal_morphology (const occ::crystal::Crystal &crystal, const occ::crystal::CrystalDimers &uc_dimers, const CrystalSurfaceEnergies &surface_energies, const occ::cg::CrystalGrowthResult &growth_result, const MorphologyOptions &options={})
	Compute the particle size/shape-dependent (surface + edge + corner) energy.

CrystalSurfaceEnergies	calculate_crystal_surface_energies (const std::string &filename, const occ::crystal::Crystal &crystal, const occ::crystal::CrystalDimers &uc_dimers, int max_number_of_surfaces, int sign=-1, double min_interplanar_spacing=0.0)
	Surface energies for the morphologically important faces.

void	to_json (nlohmann::json &j, const FacetEnergies &)

void	to_json (nlohmann::json &j, const CrystalSurfaceEnergies &)

qm::Wavefunction	geometry_optimization (const io::OccInput &config)
	Perform geometry optimization.

std::pair< qm::Wavefunction, core::VibrationalModes >	geometry_optimization_with_frequencies (const io::OccInput &config, bool run_frequencies=true)
	Perform geometry optimization with optional vibrational analysis.

MethodSpec	parse_method_string (const std::string &method_string)
	Parse a method string into base method, dispersion, kind and backend.

MethodKind	method_kind_from_string (const std::string &name)

qm::SpinorbitalKind	determine_spinorbital_kind (const std::string &name, int multiplicity, MethodKind method_kind)

occ::qm::Wavefunction	calculate_wavefunction (const occ::core::Molecule &mol, const std::string &name, const std::string &energy_model, bool spherical)

WavefunctionList	calculate_wavefunctions (const std::string &basename, const MoleculeList &molecules, const std::string &energy_model, bool spherical)

occ::qm::Wavefunction	calculate_wavefunction (const occ::core::Molecule &mol, const std::string &name, const std::string &method, const std::string &basis, bool spherical)
	Compute a wavefunction at an explicit method/basis rather than a CE model name.

WavefunctionList	calculate_wavefunctions (const std::string &basename, const MoleculeList &molecules, const std::string &method, const std::string &basis, bool spherical)

void	compute_monomer_energies (const std::string &basename, WavefunctionList &wavefunctions, const std::string &model_name)

qm::Wavefunction	single_point (const io::OccInput &)

qm::Wavefunction	single_point (const io::OccInput &, const qm::Wavefunction &)

core::VibrationalModes	vibrational_analysis (const io::OccInput &config, const qm::Wavefunction &wfn, const VibrationalAnalysisConfig &vib_config={})
	Perform vibrational frequency analysis on an optimized geometry.

core::VibrationalModes	vibrational_analysis (const io::OccInput &config, const qm::Wavefunction &wfn)
	Convenience function for standard frequency analysis.

Typedef Documentation

◆ MoleculeList

using occ::driver::MoleculeList = typedef std::vector<occ::core::Molecule>

◆ WavefunctionList

typedef std::vector< occ::qm::Wavefunction > occ::driver::WavefunctionList

Enumeration Type Documentation

◆ MethodKind

enum class occ::driver::MethodKind

strong

Enumerator
HF
DFT
MP2
CCSD
CCSD_T
GFN2

◆ SolvationModelKind

enum class occ::driver::SolvationModelKind

strong

Enumerator
None	gas phase, no solvation surfaces
Smd	SMD via a solvated DFT SCF.
CosmoRS	openCOSMO-RS 24a on an ideal-conductor cavity

◆ WavefunctionChoice

enum class occ::driver::WavefunctionChoice

strong

Enumerator
GasPhase
Solvated

Function Documentation

◆ apply_acceleration()

template<typename Proc >

void occ::driver::apply_acceleration	(	Proc &	proc,
		std::size_t	nbf,
		const io::OccInput &	config,
		bool	allow_cosx = `true`
	)

Apply the active acceleration policy (DF / COSX) to an SCF procedure.

Works for both HartreeFock and DFT (both expose the DF and COSX setters). COSX is only enabled for exact exchange, never for range-separated hybrids (COSX cannot handle range separation).

Parameters

allow_cosx pass false for gradient-producing calculations (geometry optimisation, frequencies): COSX has no analytic gradient, so it is downgraded to DF exchange there.

◆ assign_interaction_terms_to_nearest_neighbours()

std::vector< AssignedEnergy > occ::driver::assign_interaction_terms_to_nearest_neighbours	(	const crystal::CrystalDimers::MoleculeNeighbors &	neighbors,
		const std::vector< double > &	dimer_energies,
		double	cg_radius
	)

◆ available_cosmors_solvents()

std::vector< std::string > occ::driver::available_cosmors_solvents ( )

Solvent names with a cached segment ensemble, sorted.

◆ calculate_crystal_surface_energies()

CrystalSurfaceEnergies occ::driver::calculate_crystal_surface_energies	(	const std::string &	filename,
		const occ::crystal::Crystal &	crystal,
		const occ::crystal::CrystalDimers &	uc_dimers,
		int	max_number_of_surfaces,
		int	sign = `-1`,
		double	min_interplanar_spacing = `0.0`
	)

Surface energies for the morphologically important faces.

Faces are considered in Bravais-Friedel-Donnay-Harker order, largest interplanar spacing first. min_interplanar_spacing (Angstrom, positive to use) is the crystallographically meaningful cut: every face with d >= the threshold is included, so the selection never depends on where a count happens to land.

max_number_of_surfaces is the older count-based cut, kept for compatibility. It can split a Friedel pair — two distinct forms that are exactly degenerate in d whenever the point group is non-centrosymmetric — and produce an asymmetric Wulff construction, so it warns when it does. Set min_interplanar_spacing instead where you can.

◆ calculate_wavefunction() [1/2]

occ::qm::Wavefunction occ::driver::calculate_wavefunction	(	const occ::core::Molecule &	mol,
		const std::string &	name,
		const std::string &	energy_model,
		bool	spherical
	)

◆ calculate_wavefunction() [2/2]

occ::qm::Wavefunction occ::driver::calculate_wavefunction	(	const occ::core::Molecule &	mol,
		const std::string &	name,
		const std::string &	method,
		const std::string &	basis,
		bool	spherical
	)

Compute a wavefunction at an explicit method/basis rather than a CE model name.

◆ calculate_wavefunctions() [1/2]

WavefunctionList occ::driver::calculate_wavefunctions	(	const std::string &	basename,
		const MoleculeList &	molecules,
		const std::string &	energy_model,
		bool	spherical
	)

◆ calculate_wavefunctions() [2/2]

WavefunctionList occ::driver::calculate_wavefunctions	(	const std::string &	basename,
		const MoleculeList &	molecules,
		const std::string &	method,
		const std::string &	basis,
		bool	spherical
	)

◆ compute_crystal_morphology()

MorphologyResult occ::driver::compute_crystal_morphology	(	const occ::crystal::Crystal &	crystal,
		const occ::crystal::CrystalDimers &	uc_dimers,
		const CrystalSurfaceEnergies &	surface_energies,
		const occ::cg::CrystalGrowthResult &	growth_result,
		const MorphologyOptions &	options = `{}`
	)

Compute the particle size/shape-dependent (surface + edge + corner) energy.

Parameters

uc_dimers must already carry interaction energies (as produced by the cg flow via InteractionMapper); dimer.interaction_energy("Total") is read.

◆ compute_monomer_energies()

void occ::driver::compute_monomer_energies	(	const std::string &	basename,
		WavefunctionList &	wavefunctions,
		const std::string &	model_name
	)

◆ conductor_profile()

ConductorResult occ::driver::conductor_profile	(	const qm::Wavefunction &	gas_wavefunction,
		const ConductorSettings &	settings = `{}`
	)

Converge the SCF in the ideal-conductor reaction field starting from a gas-phase wavefunction, then build the segments.

◆ conductor_segments()

solvent::cosmors::Segments occ::driver::conductor_segments	(	const qm::Wavefunction &	wavefunction,
		const solvent::cosmors::Parameters &	params = `{}`,
		double	probe_radius_angs = `0.0`,
		int	angular_points = `590`,
		bool	constrain_charge = `true`,
		Vec *	dielectric_energies = `nullptr`,
		double *	cavity_volume_angs3 = `nullptr`
	)

Build segments from a wavefunction that has already been converged in the ideal-conductor reaction field, with both σ and σ⊥ averaged on params.

Reusing a cached conductor wavefunction here is the whole point of the model: the segment descriptors are solvent independent, so one calculation serves every solvent.

◆ cosmors_solvation()

CGSolvationResult occ::driver::cosmors_solvation	(	const std::string &	basename,
		const std::vector< core::Molecule > &	molecules,
		const std::vector< qm::Wavefunction > &	gas_wavefunctions,
		const SolventSpec &	solvent,
		const CosmoRSSettings &	settings = `{}`
	)

Build openCOSMO-RS solvation surfaces for each molecule in solvent.

The conductor wavefunction is solvent independent, so it is computed once per molecule and cached as <basename>_<i>_conductor.owf.json. Changing solvent then costs one apparent-surface-charge solve and a contraction, not another SCF.

Three of the model's terms are additive over surface elements and become cg channels: dielectric (gas to ideal conductor), residual (conductor to solvent), and cavity (the per-atom τ_α A_α term). The rest — combinatorial, ring, reference state and the constant η — are per-molecule with no surface-element home, so they carry no channel, but they are still added into total_solvation_energy so the reported figure is the model's whole solvation free energy. They are identical for a bulk and a surface molecule, so they cancel in the attachment-energy difference cg forms.

◆ cosmors_solvation_free_energy() [1/2]

CosmoRSSolvation occ::driver::cosmors_solvation_free_energy	(	const core::Molecule &	solute,
		const core::Molecule &	solvent,
		const CosmoRSSolvationSettings &	settings = `{}`
	)

The same, computing the solvent's conductor cavity from its geometry instead of loading a cached ensemble.

Two SCFs rather than one, but it works for any solvent.

◆ cosmors_solvation_free_energy() [2/2]

CosmoRSSolvation occ::driver::cosmors_solvation_free_energy	(	const core::Molecule &	solute,
		const std::string &	solvent_name,
		const CosmoRSSolvationSettings &	settings = `{}`
	)

Solvation free energy of solute in a named solvent, end to end.

Runs the gas-phase SCF, converges it again in the ideal-conductor reaction field, builds the segment descriptors on the model's own averaging radii, loads the solvent's cached segment ensemble and assembles the free energy. This is the whole model in one call; the pieces are available separately for callers that need them.

◆ determine_spinorbital_kind()

qm::SpinorbitalKind occ::driver::determine_spinorbital_kind	(	const std::string &	name,
		int	multiplicity,
		MethodKind	method_kind
	)

inline

◆ df_exchange_intermediate_bytes()

std::size_t occ::driver::df_exchange_intermediate_bytes	(	std::size_t	nocc,
		std::size_t	nbf,
		std::size_t	ndf
	)

inline

Bytes DF-K would need for its half-transformed intermediate.

◆ df_exchange_memory_budget()

std::size_t occ::driver::df_exchange_memory_budget ( )

inline

Decide SCF acceleration (density fitting / COSX) for a calculation.

Parameters

policy	requested RIPolicy (Auto by default)
orbital_basis_name	primary orbital basis name (for aux-basis lookup)
nbf	number of basis functions (for the COSX crossover)
exact_exchange	fraction of exact (HF) exchange: 1.0 for HF, the hybrid mixing fraction for DFT, 0.0 for a pure GGA
user_df_basis	explicit –df-basis/–aux value ("" if unset)
user_cosx	explicit –cosx flag
df_exchange_bytes	size of the DF-K intermediate, 0 if unknown

Explicit user settings always win; Auto only fills in choices left unset. The Auto rule (ORCA-style): density-fit the Coulomb term for every SCF method, and for exact exchange use DF-K below the basis-function crossover, seminumerical COSX above it.

Memory budget for the DF exchange intermediate, in bytes.

DF-K half-transforms the three-centre integrals into B[i][mu][P], which is nocc x nbf x ndf doubles. That intermediate cannot be blocked over the auxiliary index – K = sum_i B_i V^-1 B_i^T, and V^-1 couples every auxiliary function to every other – so its size is a hard requirement of the method rather than something an implementation can trade away.

COSX needs no such intermediate, which makes it the right choice once the DF-K workspace stops fitting, independent of how many basis functions there are.

◆ geometry_optimization()

qm::Wavefunction occ::driver::geometry_optimization ( const io::OccInput & config )

Perform geometry optimization.

Parameters

config Input configuration

Returns: Optimized wavefunction

◆ geometry_optimization_with_frequencies()

std::pair< qm::Wavefunction, core::VibrationalModes > occ::driver::geometry_optimization_with_frequencies	(	const io::OccInput &	config,
		bool	run_frequencies = `true`
	)

Perform geometry optimization with optional vibrational analysis.

Parameters

config	Input configuration
run_frequencies	If true, compute vibrational frequencies after optimization

Returns: Pair of optimized wavefunction and vibrational modes (empty if not computed)

◆ make_cg_solvation_model()

std::unique_ptr< CGSolvationModel > occ::driver::make_cg_solvation_model	(	SolvationModelKind	kind,
		const CGSolvationSettings &	settings
	)

◆ method_kind_from_string()

MethodKind occ::driver::method_kind_from_string ( const std::string & name )

inline

◆ parse_method_string()

MethodSpec occ::driver::parse_method_string ( const std::string & method_string )

inline

Parse a method string into base method, dispersion, kind and backend.

Single source of truth: a leading "ri-"/"df-"/"thc-" backend prefix (only for correlation methods) is split off, then a dispersion suffix, then the base is classified. Anything not matching a known method alias is a DFT functional.

Examples: "pbe-d4" -> {base "pbe", disp "d4", kind DFT} "hf-d4" -> {base "hf", disp "d4", kind HF} "ccsd(t)" -> {base "ccsd(t)", kind CCSD_T, backend ""} "ri-ccsd(t)" -> {base "ccsd(t)", kind CCSD_T, backend "df"} "thc-mp2" -> {base "mp2", kind MP2, backend "thc"} "b97-d" -> {base "b97-d", kind DFT} (prefix/suffix kept)

◆ parse_solvation_model()

SolvationModelKind occ::driver::parse_solvation_model ( const std::string & )

◆ plan_acceleration()

AccelerationPlan occ::driver::plan_acceleration	(	io::RIPolicy	policy,
		const std::string &	orbital_basis_name,
		std::size_t	nbf,
		double	exact_exchange,
		const std::string &	user_df_basis,
		bool	user_cosx,
		std::size_t	df_exchange_bytes = `0`
	)

inline

◆ prepare_cg()

CGPreparation occ::driver::prepare_cg ( CGConfig const & config )

Load the crystal and build calculator options + charges from config.

◆ run_cg()

occ::cg::CrystalGrowthResult occ::driver::run_cg ( CGConfig const & )

◆ run_cg_pipeline()

occ::cg::CrystalGrowthResult occ::driver::run_cg_pipeline	(	CrystalGrowthCalculator &	calc,
		const CrystalGrowthCalculatorOptions &	opts,
		CGConfig const &	config
	)

Run the full crystal-growth pipeline on an already-constructed calculator: monomer energies -> lattice convergence -> molecular surroundings -> surface energies / morphology -> JSON serialization.

◆ run_correlation()

CorrelationResult occ::driver::run_correlation	(	const qm::Wavefunction &	wfn,
		const CorrelationOptions &	opts = `{}`
	)

Run an MP2 / CCSD / CCSD(T) calculation on a converged SCF wavefunction, with the same backend dispatch, auxiliary-basis resolution and frozen-core handling as the CLI.

Handles restricted and unrestricted references.

◆ single_point() [1/2]

qm::Wavefunction occ::driver::single_point ( const io::OccInput & )

◆ single_point() [2/2]

qm::Wavefunction occ::driver::single_point	(	const io::OccInput &	,
		const qm::Wavefunction &
	)

◆ solvation_model_name()

std::string occ::driver::solvation_model_name ( SolvationModelKind )

◆ to_json() [1/2]

void occ::driver::to_json	(	nlohmann::json &	j,
		const CrystalSurfaceEnergies &
	)

◆ to_json() [2/2]

void occ::driver::to_json	(	nlohmann::json &	j,
		const FacetEnergies &
	)

◆ vibrational_analysis() [1/2]

core::VibrationalModes occ::driver::vibrational_analysis	(	const io::OccInput &	config,
		const qm::Wavefunction &	wfn
	)

Convenience function for standard frequency analysis.

Uses default settings optimized for most common use cases:

Finite differences with acoustic sum rule
Step size: 0.005 Bohr
No projection of translational/rotational modes

Parameters

config	Input configuration from OCC input file
wfn	Converged wavefunction from optimization or single point

Returns: VibrationalModes Complete vibrational analysis results

◆ vibrational_analysis() [2/2]

core::VibrationalModes occ::driver::vibrational_analysis	(	const io::OccInput &	config,
		const qm::Wavefunction &	wfn,
		const VibrationalAnalysisConfig &	vib_config = `{}`
	)

Perform vibrational frequency analysis on an optimized geometry.

This function computes the molecular Hessian using finite differences and performs normal mode analysis to obtain vibrational frequencies. It can be called after geometry optimization to characterize the stationary point.

Parameters

config	Input configuration from OCC input file
wfn	Converged wavefunction from optimization or single point
vib_config	Configuration options for vibrational analysis

Returns: VibrationalModes Complete vibrational analysis results

Namespaces

Classes

Typedefs

Enumerations

Functions

Typedef Documentation

◆ MoleculeList

◆ WavefunctionList

Enumeration Type Documentation

◆ MethodKind

◆ SolvationModelKind

◆ WavefunctionChoice

Function Documentation

◆ apply_acceleration()

◆ assign_interaction_terms_to_nearest_neighbours()

◆ available_cosmors_solvents()

◆ calculate_crystal_surface_energies()

◆ calculate_wavefunction() [1/2]

◆ calculate_wavefunction() [2/2]

◆ calculate_wavefunctions() [1/2]

◆ calculate_wavefunctions() [2/2]

◆ compute_crystal_morphology()

◆ compute_monomer_energies()

◆ conductor_profile()

◆ conductor_segments()

◆ cosmors_solvation()

◆ cosmors_solvation_free_energy() [1/2]

◆ cosmors_solvation_free_energy() [2/2]

◆ determine_spinorbital_kind()

◆ df_exchange_intermediate_bytes()

◆ df_exchange_memory_budget()

◆ geometry_optimization()

◆ geometry_optimization_with_frequencies()

◆ make_cg_solvation_model()

◆ method_kind_from_string()

◆ parse_method_string()

◆ parse_solvation_model()

◆ plan_acceleration()

◆ prepare_cg()

◆ run_cg()

◆ run_cg_pipeline()

◆ run_correlation()

◆ single_point() [1/2]

◆ single_point() [2/2]

◆ solvation_model_name()

◆ to_json() [1/2]

◆ to_json() [2/2]

◆ vibrational_analysis() [1/2]

◆ vibrational_analysis() [2/2]