Namespace qdk::chemistry::constants

namespace constants

Functions

inline std::unordered_map<std::string, ConstantInfo> get_constants_info()

Get documentation information for all constants in the current namespace.

This function returns documentation for constants using the currently active CODATA version (determined by the using namespace directive below).

Returns:

Map of constant names to their documentation

constexpr const char *get_current_codata_version()

Variables

static constexpr std::array<std::array<size_t, 4>, 119> ATOMIC_CONFIGURATION

Non-relativistic spin-restricted spherical HF configurations.

Each entry corresponds to an element with atomic number Z and contains the number of electrons in each subshell: s, p, d, f

Reference: Lehtola, S. (2020). “Fully numerical calculations on atoms with

fractional occupations and range-separated functionals” Phys. Rev. A. 10.1103/physreva.101.012516

struct ConstantInfo
#include <qdk/chemistry/constants.hpp>

Documentation metadata for physical constants.

Public Members

std::string description
std::string name
std::string source
std::string symbol
std::string units
double value
namespace codata_2014

CODATA 2014 recommended values for fundamental physical constants.

Constants from the 2014 CODATA recommended values of the fundamental physical constants: https://physics.nist.gov/cuu/Constants/. :cite:Mohr2016

Variables

static constexpr double angstrom_to_bohr = 1.0 / bohr_to_angstrom
static constexpr double atomic_mass_constant = 1.660539040e-27
static constexpr double avogadro_constant = 6.022140857e23
static constexpr double bohr_to_angstrom = 0.52917721067
static constexpr double boltzmann_constant = 1.38064852e-23
static constexpr double electron_mass = 9.10938356e-31
static constexpr double elementary_charge = 1.6021766208e-19
static constexpr double ev_to_hartree = 1.0 / hartree_to_ev
static constexpr double fine_structure_constant = 7.2973525664e-3
static constexpr double hartree_to_ev = 27.21138602
static constexpr double hartree_to_kcal_per_mol = 627.509474
static constexpr double hartree_to_kj_per_mol = 2625.49964
static constexpr double kcal_per_mol_to_hartree = 1.0 / hartree_to_kcal_per_mol
static constexpr double kj_per_mol_to_hartree = 1.0 / hartree_to_kj_per_mol
static constexpr double neutron_mass = 1.674927471e-27
static constexpr double planck_constant = 6.626070040e-34
static constexpr double proton_mass = 1.672621898e-27
static constexpr double reduced_planck_constant = planck_constant / (2.0 * 3.14159265358979323846)
static constexpr double speed_of_light = 299792458.0
namespace codata_2018

CODATA 2018 recommended values for fundamental physical constants.

Constants from the 2018 CODATA recommended values of the fundamental physical constants: https://physics.nist.gov/cuu/Constants/. :cite:Tiesinga2021

Variables

static constexpr double angstrom_to_bohr = 1.0 / bohr_to_angstrom
static constexpr double atomic_mass_constant = 1.66053906660e-27
static constexpr double avogadro_constant = 6.02214076e23
static constexpr double bohr_to_angstrom = 0.529177210903
static constexpr double boltzmann_constant = 1.380649e-23
static constexpr double electron_mass = 9.1093837015e-31
static constexpr double elementary_charge = 1.602176634e-19
static constexpr double ev_to_hartree = 1.0 / hartree_to_ev
static constexpr double fine_structure_constant = 7.2973525693e-3
static constexpr double hartree_to_ev = 27.211386245988
static constexpr double hartree_to_kcal_per_mol = 627.5094736
static constexpr double hartree_to_kj_per_mol = 2625.4996395
static constexpr double kcal_per_mol_to_hartree = 1.0 / hartree_to_kcal_per_mol
static constexpr double kj_per_mol_to_hartree = 1.0 / hartree_to_kj_per_mol
static constexpr double neutron_mass = 1.67492749804e-27
static constexpr double planck_constant = 6.62607015e-34
static constexpr double proton_mass = 1.67262192369e-27
static constexpr double reduced_planck_constant = planck_constant / (2.0 * 3.14159265358979323846)
static constexpr double speed_of_light = 299792458.0
namespace codata_2022

CODATA 2022 recommended values for fundamental physical constants.

Constants from the 2022 CODATA recommended values of the fundamental physical constants: https://physics.nist.gov/cuu/Constants/. :cite:Mohr2025

Variables

static constexpr double angstrom_to_bohr = 1.0 / bohr_to_angstrom
static constexpr double atomic_mass_constant = 1.66053906892e-27
static constexpr double avogadro_constant = 6.02214076e23
static constexpr double bohr_to_angstrom = 0.529177210544
static constexpr double boltzmann_constant = 1.380649e-23
static constexpr double electron_mass = 9.1093837139e-31
static constexpr double elementary_charge = 1.602176634e-19
static constexpr double ev_to_hartree = 1.0 / hartree_to_ev
static constexpr double fine_structure_constant = 7.2973525643e-3
static constexpr double hartree_to_ev = 27.211386245981
static constexpr double hartree_to_kcal_per_mol = hartree_to_kj_per_mol / 4.184
static constexpr double hartree_to_kj_per_mol = hartree_to_ev * 1.602176634 * 6.02214076 * 10
static constexpr double kcal_per_mol_to_hartree = 1.0 / hartree_to_kcal_per_mol
static constexpr double kj_per_mol_to_hartree = 1.0 / hartree_to_kj_per_mol
static constexpr double neutron_mass = 1.67492750056e-27
static constexpr double planck_constant = 6.62607015e-34
static constexpr double proton_mass = 1.67262192595e-27
static constexpr double reduced_planck_constant = planck_constant / (2.0 * 3.14159265358979323846)
static constexpr double speed_of_light = 299792458.0