q3::dispersion Namespace Reference

Classes
struct	C6ReferencePoint
	One (CN_i, CN_j) -> C6 grid point for an ordered element pair (Z_i, Z_j). More...

Functions
const std::array< C6ReferencePoint, number_of_c6_reference_points > &	c6_reference_table ()
Real	r2r4_by_atomic_number (int atomic_number)
	sqrt(0.5 * <r^4>/<r^2> * sqrt(Z)) atomic values, indexed by atomic number (1-based).
Real	rcov_by_atomic_number (int atomic_number)
	D3 covalent radii (Pyykko-Atsumi, metals scaled -10%), indexed by atomic number.

Variables
constexpr int	number_of_c6_reference_points = 484

Detailed Description

DFT-D3(BJ) reference data for elements currently supported by Q3.

Physical constants (coordination-number-dependent C6 dispersion coefficients, covalent radii, <r^4>/<r^2> ratios), not source code: extracted from the tables published in

S. Grimme, J. Antony, S. Ehrlich, H. Krieg, J. Chem. Phys. 132, 154104 (2010) S. Grimme, S. Ehrlich, L. Goerigk, J. Comput. Chem. 32, 1456 (2011) (Becke-Johnson damping)

and cross-checked against Quantum ESPRESSO's dft-d3 module (a GPL-licensed repackaging of Grimme's reference code) purely to confirm which published values it uses – this file is an original, independent re-implementation covering only the elements Q3 currently supports (Si, Cu, Fe, Ni, Cr, C), not a derivative of that GPL source.

C6ReferencePoint entries are the (CN_i, CN_j, C6) grid used by the Gaussian-weighted coordination-number interpolation (Grimme 2010, eq. 8); r2r4/rcov are indexed directly by atomic number. Entries are pre-symmetrized (both (Z_i,Z_j) and (Z_j,Z_i) orderings present) so callers need only match (Z_i, Z_j) directly, never the swap.

Function Documentation

c6_reference_table()

const std::array< C6ReferencePoint, number_of_c6_reference_points > & q3::dispersion::c6_reference_table ( )

inline

Reference grid restricted to element pairs among {C, Si, Cr, Fe, Ni, Cu}. Pre-symmetrized: query (Z_i, Z_j) directly, both orderings are present.

Definition at line 90 of file d3bj_reference_data.hpp.

r2r4_by_atomic_number()

Real q3::dispersion::r2r4_by_atomic_number ( int  atomic_number )

inline

sqrt(0.5 * <r^4>/<r^2> * sqrt(Z)) atomic values, indexed by atomic number (1-based).

Definition at line 36 of file d3bj_reference_data.hpp.

Referenced by q3::D3BJDispersionCalculator::compute_energy(), and q3::D3BJDispersionCalculator::compute_gradients().

rcov_by_atomic_number()

Real q3::dispersion::rcov_by_atomic_number ( int  atomic_number )

inline

D3 covalent radii (Pyykko-Atsumi, metals scaled -10%), indexed by atomic number.

Definition at line 56 of file d3bj_reference_data.hpp.

Referenced by q3::D3BJDispersionCalculator::compute_energy(), and q3::D3BJDispersionCalculator::compute_gradients().

Variable Documentation

number_of_c6_reference_points

constexpr int q3::dispersion::number_of_c6_reference_points = 484

constexpr

Definition at line 84 of file d3bj_reference_data.hpp.