occ::xtb::CpcmXSolvationModel Class Reference

CPCM-X (xtb-flavoured CPCM) implicit-solvent model. More...

#include <cpcmx.h>

Inheritance diagram for occ::xtb::CpcmXSolvationModel:

Collaboration diagram for occ::xtb::CpcmXSolvationModel:

Public Member Functions
	CpcmXSolvationModel (CpcmXOptions opts={})
void	initialize (const Mat3N &positions_bohr, const IVec &atomic_numbers) override
void	update (const Vec &atomic_charges) override
const Vec &	atom_potential () const override
double	energy () const override
std::string	name () const override
std::optional< SolvationSurfaces >	surfaces () const override
	Optional per-element decomposition of the latest solvation contribution.
Mat3N	gradient () const override
	Analytical gradient of the solvation energy with respect to atomic positions (Hartree/Bohr, 3 × N_atoms).
size_t	num_surface_points () const
	Number of cavity surface elements (post-masking).
const occ::solvent::surface::Surface &	surface () const
const Vec &	surface_charges () const
	Surface apparent charge σ at the most recent update().
double	dielectric () const
double	f_epsilon () const
const occ::scrf::ReactionFieldEngine &	engine () const
	Access the underlying engine (for inspection / tests).
virtual void	update (const Vec &atomic_charges)=0
virtual void	update (const Vec &atomic_charges, const Mat3N &, const Mat &)
	Update from the atomic charges together with the CAMM atomic dipoles (3 × N) and traceless quadrupoles (6 × N, CammMoments::qp layout), so the anisotropic part of the density polarises the continuum too.
Public Member Functions inherited from occ::xtb::XtbSolvationModel
virtual	~XtbSolvationModel ()=default
virtual void	set_multipole_damping (const Vec &, double, double)
	Hand the model the solute's own short-range damping radii for the atom→cavity dipole and quadrupole kernels, so a multipolar reaction field treats the CAMM moments the way the rest of the method does.
virtual const Mat3N &	dipole_potential () const
	Conjugates of the atomic dipoles and quadrupoles at the last update: ∂E_solv/∂μ (3 × N) and ∂E_solv/∂Θ (6 × N, same layout as the input).
virtual const Mat &	quadrupole_potential () const
virtual const Vec &	damping_radius_gradient () const
	∂E_solv/∂R_co per atom, for damping radii that depend on the geometry.

Detailed Description

CPCM-X (xtb-flavoured CPCM) implicit-solvent model.

Treats each atom as a point charge of magnitude q_atom (the SCC's converged Mulliken charge) producing an electrostatic potential φ_i = Σ_a q_atom_a / |r_i − R_a| at cavity point i. Solves the COSMO linear system A σ = −f(ε) φ for surface charges σ, then folds back the atom-resolved screening potential V_solv_a = Σ_i σ_i / |R_a − r_i|. The variational solvation energy is E_solv = ½ q · V_solv = ½ σ · φ.

Implementation is a thin adapter over occ::scrf::ReactionFieldEngine (Phase 2). Kept as its own class because the SCC interacts with solvation via the XtbSolvationModel virtual contract; the engine itself is just the shared CPCM/COSMO math.

Constructor & Destructor Documentation

CpcmXSolvationModel()

occ::xtb::CpcmXSolvationModel::CpcmXSolvationModel ( CpcmXOptions  opts = {} )

explicit

Member Function Documentation

atom_potential()

const Vec & occ::xtb::CpcmXSolvationModel::atom_potential ( ) const

inlineoverridevirtual

Implements occ::xtb::XtbSolvationModel.

dielectric()

double occ::xtb::CpcmXSolvationModel::dielectric ( ) const

inline

energy()

double occ::xtb::CpcmXSolvationModel::energy ( ) const

inlineoverridevirtual

Implements occ::xtb::XtbSolvationModel.

engine()

const occ::scrf::ReactionFieldEngine & occ::xtb::CpcmXSolvationModel::engine ( ) const

inline

Access the underlying engine (for inspection / tests).

f_epsilon()

double occ::xtb::CpcmXSolvationModel::f_epsilon ( ) const

inline

gradient()

Mat3N occ::xtb::CpcmXSolvationModel::gradient ( ) const

inlineoverridevirtual

Analytical gradient of the solvation energy with respect to atomic positions (Hartree/Bohr, 3 × N_atoms).

Frozen-cavity convention — the cavity points move rigidly with their parent atoms and per-element areas are constant. Concrete models override; the default returns an empty matrix so callers can detect "no gradient available" without surprise.

Reimplemented from occ::xtb::XtbSolvationModel.

initialize()

void occ::xtb::CpcmXSolvationModel::initialize ( const Mat3N &  positions_bohr, const IVec &  atomic_numbers  )

overridevirtual

Implements occ::xtb::XtbSolvationModel.

name()

std::string occ::xtb::CpcmXSolvationModel::name ( ) const

overridevirtual

Implements occ::xtb::XtbSolvationModel.

num_surface_points()

size_t occ::xtb::CpcmXSolvationModel::num_surface_points ( ) const

inline

Number of cavity surface elements (post-masking).

May be zero for an empty / pathological input.

surface()

const occ::solvent::surface::Surface & occ::xtb::CpcmXSolvationModel::surface ( ) const

inline

surface_charges()

const Vec & occ::xtb::CpcmXSolvationModel::surface_charges ( ) const

inline

Surface apparent charge σ at the most recent update().

Empty until update() is called.

surfaces()

std::optional< SolvationSurfaces > occ::xtb::CpcmXSolvationModel::surfaces ( ) const

overridevirtual

Optional per-element decomposition of the latest solvation contribution.

Concrete models (CPCM-X, SMD) override; the default returns std::nullopt. Reflects the state at the most recent update(q).

Reimplemented from occ::xtb::XtbSolvationModel.

update() [1/3]

void occ::xtb::CpcmXSolvationModel::update ( const Vec &  atomic_charges )

overridevirtual

Implements occ::xtb::XtbSolvationModel.

update() [2/3]

virtual void occ::xtb::XtbSolvationModel::update ( const Vec &  atomic_charges )

virtual

Implements occ::xtb::XtbSolvationModel.

update() [3/3]

virtual void occ::xtb::XtbSolvationModel::update ( const Vec &  atomic_charges, const Mat3N &  , const Mat &    )

inlinevirtual

Update from the atomic charges together with the CAMM atomic dipoles (3 × N) and traceless quadrupoles (6 × N, CammMoments::qp layout), so the anisotropic part of the density polarises the continuum too.

The default drops them, which leaves charge-only models unchanged.

Reimplemented from occ::xtb::XtbSolvationModel.

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The documentation for this class was generated from the following file:

• /home/runner/work/occ/occ/include/occ/xtb/cpcmx.h