occ::driver Namespace Reference

Namespaces
namespace	impl

Classes
struct	AccelerationPlan
struct	AssignedEnergy
class	CEModelCrystalGrowthCalculator
struct	CGConfig
class	CrystalGrowthCalculator
struct	CrystalGrowthCalculatorOptions
struct	CrystalSurfaceEnergies
struct	DMAConfig
class	DMADriver
class	DummyCrystalGrowthCalculator
struct	FacetEnergies
struct	MethodSpec
struct	VibrationalAnalysisConfig
	Configuration options for vibrational frequency analysis. More...
class	XTBCrystalGrowthCalculator

Typedefs
using	WavefunctionList = std::vector< Wavefunction >
using	SolventNeighborContributionList = std::vector< cg::SolvationContribution >
using	MoleculeList = std::vector< occ::core::Molecule >

Enumerations
enum class	WavefunctionChoice { GasPhase , Solvated }
enum class	MethodKind {   HF , DFT , MP2 , CCSD ,   CCSD_T , GFN2 }

Functions
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)
	Decide SCF acceleration (density fitting / COSX) for a calculation.
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.
occ::cg::CrystalGrowthResult	run_cg (CGConfig const &)
std::vector< AssignedEnergy >	assign_interaction_terms_to_nearest_neighbours (const crystal::CrystalDimers::MoleculeNeighbors &neighbors, const std::vector< double > &dimer_energies, double cg_radius)
std::vector< occ::Vec3 >	calculate_net_dipole (const WavefunctionList &wavefunctions, const crystal::CrystalDimers &crystal_dimers)
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)
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)
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>

SolventNeighborContributionList

using occ::driver::SolventNeighborContributionList = typedef std::vector<cg::SolvationContribution>

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

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
	)

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
	)

calculate_net_dipole()

std::vector< occ::Vec3 > occ::driver::calculate_net_dipole	(	const WavefunctionList &	wavefunctions,
		const crystal::CrystalDimers &	crystal_dimers
	)

calculate_wavefunction()

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

calculate_wavefunctions()

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

compute_monomer_energies()

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

determine_spinorbital_kind()

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

inline

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)

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)

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  )

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

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.

run_cg()

occ::cg::CrystalGrowthResult occ::driver::run_cg

(

CGConfig const &

)

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 &
	)

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