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High-precision calculations for one- and two-valence atomic systems
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Variables
PhysConst Namespace Reference

Set of commonly-used Physics constants. More...

Variables

constexpr double c_SI = 299792458.0
 c, speed of light: 299 792 458 m/s [exact]
 
constexpr double h_SI = (6.62607015e-34)
 Planck constant h: 6.626 070 15 e-34 J.s [exact].
 
constexpr double hbar_SI = h_SI / (2.0 * M_PI)
 hbar: 6.626 070 15 e-34 / (2 Pi) J.s [exact]
 
constexpr double e_C = 1.602176634e-19
 Fundamental charge, Coulombs. 1.602 176 634 e-19 C [exact].
 
constexpr double alpha = 1.0 / 137.035999177
 Fine-structure constant: alpha = 1/137.035 999 177(21) [CODATA 2022].
 
constexpr double g_e = -2.00231930436092
 electron g-factor: -2.002 319 304 360 92(36) [CODATA 2022]
 
constexpr double e_on_me_SI = 1.75882000838e11
 e/me: 1.758 820 008 38(55) e11 [CODATA 2022]
 
constexpr double m_e_kg = e_C / e_on_me_SI
 electron mass, in SI (kg)
 
constexpr double m_p = 1836.152673426
 Proton mass, in atomic units (mp/me). CODATA 2022: 1836.152 673 426(32)
 
constexpr double m_muon = 206.7682827
 muon mass in atomic units (m_mu/m_e). Codata 2022: 206.768 2827(46)
 
constexpr double m_tau = 3477.23
 tauon mass in atomic units (m_tau/m_e) 3477.23(23)
 
constexpr double u_NMU_kg = 1.66053906892e-27
 unified atomic mass unit; (nuclear mass unit, Dalton): CODATA 2022: 1.660 539 068 92(52) x 10-27 kg
 
constexpr double aB_m = hbar_SI / (m_e_kg * c_SI * alpha)
 Bohr radius, in m. : hbar/(m_e*c*alpha)
 
constexpr double Hartree_eV = 27.211386245981
 Hartree (atomic energy unit = 2Ry) in eV, 27.211 386 245 981(30) eV [CODATA 2022].
 
constexpr double GF_GeV2 = 1.1663787e-5
 Fermi weak constant, in GeV^-2: 1.166 3787(6) x 10-5 GeV-2 [CODATA 2022].
 
constexpr double alpha2 = alpha * alpha
 
constexpr double c = 1.0 / alpha
 speed of light in a.u. (=1/alpha)
 
constexpr double c2 = c * c
 
constexpr double hbarc_MeVfm = (hbar_SI * c_SI / e_C) * 1.0e9
 hbar * c, in MeV.fm
 
constexpr double m_e_MeV = Hartree_eV * c2 / 1.0e6
 Electron mass (MeV/c^2)
 
constexpr double u_NMU = u_NMU_kg / m_e_kg
 unified atomic mass unit; (nuclear mass unit, Dalton): au
 
constexpr double aB_cm = aB_m * (1.0e+2)
 
constexpr double aB_fm = aB_m * (1.0e+15)
 
constexpr double aB_nm = aB_m * (1.0e+9)
 
constexpr double Hartree_Hz = Hartree_eV * e_C / h_SI
 Hartree (atomic energy unit = 2Ry) in Hz.
 
constexpr double Hartree_MHz = Hartree_Hz * (1.0e-6)
 
constexpr double Hartree_GHz = Hartree_Hz * (1.0e-9)
 
constexpr double Hartree_invcm = 1.0 / (2.0 * M_PI * c * aB_cm)
 Hartree to cm^-1 conversion [wave-number, inverse cm]:
 
constexpr double HartreeWL_nm = 2.0 * M_PI * c * aB_m * (1.0e+9)
 Hartree to corresponding wavelength, in nm.
 
constexpr double hbar_on_EH = hbar_SI / e_C / Hartree_eV
 hbar/E_H (atomic unit of time) (in seconds)
 
constexpr double muB_SI = 0.5
 Bohr magneton (in SI-derived atomic units):
 
constexpr double muB_CGS = 0.5 * alpha
 Bohr magneton (in Gaussian CGS-derived atomic units):
 
constexpr double muN_SI = muB_SI / m_p
 Nulcear magneton (in SI-derived atomic units):
 
constexpr double muN_CGS = muB_CGS / m_p
 Nulcear magneton (in Gaussian CGS-derived atomic units):
 
constexpr double muN_CGS_MHz = Hartree_MHz * muB_CGS / m_p
 Nulcear magneton in MHz (via Gaussian CGS-derived atomic units):
 
constexpr double barn_m2 = 1.0e-28
 barn = 1.0e-28m^2, for Quadrupole moment
 
constexpr double barn_au = barn_m2 / (aB_m * aB_m)
 
constexpr double barn_MHz = barn_au * Hartree_MHz
 
constexpr double GF = GF_GeV2 * alpha * m_e_MeV * m_e_MeV * 1e-6
 Fermi weak constant (au).
 
constexpr double GFe11 = GF * 1.0e11
 Fermi weak constant * 10^11, in atomic units.
 

Detailed Description

Set of commonly-used Physics constants.

Constains physical constants, and units conversions. Taken mostly from 2018 CODATA values. https://physics.nist.gov/cuu/Constants/

Variable Documentation

◆ c_SI

constexpr double PhysConst::c_SI = 299792458.0
constexpr

c, speed of light: 299 792 458 m/s [exact]

◆ h_SI

constexpr double PhysConst::h_SI = (6.62607015e-34)
constexpr

Planck constant h: 6.626 070 15 e-34 J.s [exact].

◆ hbar_SI

constexpr double PhysConst::hbar_SI = h_SI / (2.0 * M_PI)
constexpr

hbar: 6.626 070 15 e-34 / (2 Pi) J.s [exact]

◆ e_C

constexpr double PhysConst::e_C = 1.602176634e-19
constexpr

Fundamental charge, Coulombs. 1.602 176 634 e-19 C [exact].

◆ alpha

constexpr double PhysConst::alpha = 1.0 / 137.035999177
constexpr

Fine-structure constant: alpha = 1/137.035 999 177(21) [CODATA 2022].

◆ g_e

constexpr double PhysConst::g_e = -2.00231930436092
constexpr

electron g-factor: -2.002 319 304 360 92(36) [CODATA 2022]

◆ e_on_me_SI

constexpr double PhysConst::e_on_me_SI = 1.75882000838e11
constexpr

e/me: 1.758 820 008 38(55) e11 [CODATA 2022]

◆ m_e_kg

constexpr double PhysConst::m_e_kg = e_C / e_on_me_SI
constexpr

electron mass, in SI (kg)

◆ m_p

constexpr double PhysConst::m_p = 1836.152673426
constexpr

Proton mass, in atomic units (mp/me). CODATA 2022: 1836.152 673 426(32)

◆ m_muon

constexpr double PhysConst::m_muon = 206.7682827
constexpr

muon mass in atomic units (m_mu/m_e). Codata 2022: 206.768 2827(46)

◆ m_tau

constexpr double PhysConst::m_tau = 3477.23
constexpr

tauon mass in atomic units (m_tau/m_e) 3477.23(23)

◆ u_NMU_kg

constexpr double PhysConst::u_NMU_kg = 1.66053906892e-27
constexpr

unified atomic mass unit; (nuclear mass unit, Dalton): CODATA 2022: 1.660 539 068 92(52) x 10-27 kg

◆ aB_m

constexpr double PhysConst::aB_m = hbar_SI / (m_e_kg * c_SI * alpha)
constexpr

Bohr radius, in m. : hbar/(m_e*c*alpha)

◆ Hartree_eV

constexpr double PhysConst::Hartree_eV = 27.211386245981
constexpr

Hartree (atomic energy unit = 2Ry) in eV, 27.211 386 245 981(30) eV [CODATA 2022].

◆ GF_GeV2

constexpr double PhysConst::GF_GeV2 = 1.1663787e-5
constexpr

Fermi weak constant, in GeV^-2: 1.166 3787(6) x 10-5 GeV-2 [CODATA 2022].

◆ c

constexpr double PhysConst::c = 1.0 / alpha
constexpr

speed of light in a.u. (=1/alpha)

◆ hbarc_MeVfm

constexpr double PhysConst::hbarc_MeVfm = (hbar_SI * c_SI / e_C) * 1.0e9
constexpr

hbar * c, in MeV.fm

◆ m_e_MeV

constexpr double PhysConst::m_e_MeV = Hartree_eV * c2 / 1.0e6
constexpr

Electron mass (MeV/c^2)

◆ u_NMU

constexpr double PhysConst::u_NMU = u_NMU_kg / m_e_kg
constexpr

unified atomic mass unit; (nuclear mass unit, Dalton): au

◆ Hartree_Hz

constexpr double PhysConst::Hartree_Hz = Hartree_eV * e_C / h_SI
constexpr

Hartree (atomic energy unit = 2Ry) in Hz.

◆ Hartree_invcm

constexpr double PhysConst::Hartree_invcm = 1.0 / (2.0 * M_PI * c * aB_cm)
constexpr

Hartree to cm^-1 conversion [wave-number, inverse cm]:

◆ HartreeWL_nm

constexpr double PhysConst::HartreeWL_nm = 2.0 * M_PI * c * aB_m * (1.0e+9)
constexpr

Hartree to corresponding wavelength, in nm.

◆ hbar_on_EH

constexpr double PhysConst::hbar_on_EH = hbar_SI / e_C / Hartree_eV
constexpr

hbar/E_H (atomic unit of time) (in seconds)

◆ muB_SI

constexpr double PhysConst::muB_SI = 0.5
constexpr

Bohr magneton (in SI-derived atomic units):

◆ muB_CGS

constexpr double PhysConst::muB_CGS = 0.5 * alpha
constexpr

Bohr magneton (in Gaussian CGS-derived atomic units):

◆ muN_SI

constexpr double PhysConst::muN_SI = muB_SI / m_p
constexpr

Nulcear magneton (in SI-derived atomic units):

◆ muN_CGS

constexpr double PhysConst::muN_CGS = muB_CGS / m_p
constexpr

Nulcear magneton (in Gaussian CGS-derived atomic units):

◆ muN_CGS_MHz

constexpr double PhysConst::muN_CGS_MHz = Hartree_MHz * muB_CGS / m_p
constexpr

Nulcear magneton in MHz (via Gaussian CGS-derived atomic units):

◆ barn_m2

constexpr double PhysConst::barn_m2 = 1.0e-28
constexpr

barn = 1.0e-28m^2, for Quadrupole moment

◆ GF

constexpr double PhysConst::GF = GF_GeV2 * alpha * m_e_MeV * m_e_MeV * 1e-6
constexpr

Fermi weak constant (au).

Particle Data Group 2020: Gf = 1.1663787(6) e-5 (hbar*c)^3 GeV^-2 = 1.1663787(6) e-5 alpha (GeV/c^2)^-2 au me = 0.51099895000 e-3 GeV/c^2 = 1 au Gf = 2.222516(11) e-3 au

◆ GFe11

constexpr double PhysConst::GFe11 = GF * 1.0e11
constexpr

Fermi weak constant * 10^11, in atomic units.