Abstract interface for an implicit-solvent contribution to a GFN-xTB SCC. More...

#include <solvation_interface.h>

Inheritance diagram for occ::xtb::XtbSolvationModel:

Public Member Functions
virtual	~XtbSolvationModel ()=default

virtual void	initialize (const Mat3N &positions_bohr, const IVec &atomic_numbers)=0

virtual void	update (const Vec &atomic_charges)=0

virtual const Vec &	atom_potential () const =0

virtual double	energy () const =0

virtual std::string	name () const =0

virtual std::optional< SolvationSurfaces >	surfaces () const
	Optional per-element decomposition of the latest solvation contribution.

virtual Mat3N	gradient () const
	Analytical gradient of the solvation energy with respect to atomic positions (Hartree/Bohr, 3 × N_atoms).

Detailed Description

Abstract interface for an implicit-solvent contribution to a GFN-xTB SCC.

Concrete models (CPCM-X in Phase 7B, SMD in Phase 7C) implement an atom-resolved potential shift folded into the per-shell isotropic V plus a scalar energy term added to the SCC breakdown. The contract is:

initialize(positions, Z) is called once at the top of an SCC, after the engine has built its geometry caches. The model sizes its internal buffers and (re)builds the cavity here.
update(atom_charges) is called at the start of every SCC iteration with the input-iter atomic Mulliken charges (length = N_atoms). The model solves its surface response and caches energy + potential.
atom_potential() returns the cached per-atom V_solv (Hartree), length = N_atoms. The engine adds V_solv[atom_of(s)] to the per-shell iso V before forming H.
energy() returns the cached scalar contribution to scc_energy, Hartree, evaluated against the same atom_charges passed to update().

NullSolvationModel below is a no-op implementation used as a gate during Phase 7A — it must not perturb gas-phase numbers.

Constructor & Destructor Documentation

◆ ~XtbSolvationModel()

virtual occ::xtb::XtbSolvationModel::~XtbSolvationModel ( )

virtualdefault

Member Function Documentation

◆ atom_potential()

virtual const Vec & occ::xtb::XtbSolvationModel::atom_potential ( ) const

pure virtual

Implemented in occ::xtb::CpcmXSolvationModel, occ::xtb::SmdSolvationModel, and occ::xtb::NullSolvationModel.

◆ energy()

virtual double occ::xtb::XtbSolvationModel::energy ( ) const

pure virtual

Implemented in occ::xtb::CpcmXSolvationModel, occ::xtb::SmdSolvationModel, and occ::xtb::NullSolvationModel.

◆ gradient()

virtual Mat3N occ::xtb::XtbSolvationModel::gradient ( ) const

inlinevirtual

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 in occ::xtb::CpcmXSolvationModel, and occ::xtb::SmdSolvationModel.