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update a few constants and uncertainties with 2022 CODATA #426

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phlptp merged 2 commits into from
Feb 10, 2026
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update a few constants and uncertainties with 2022 CODATA #426

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update a few constants and uncertainties with 2022 CODATA
phlptp Feb 9, 2026
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[pre-commit.ci] auto fixes from pre-commit.com hooks
pre-commit-ci[bot] Feb 9, 2026
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2 changes: 1 addition & 1 deletion units/unit_definitions.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -826,7 +826,7 @@ namespace precise {
33.5,
precise::mega* precise::J}; // liter of gasoline equivalent
constexpr precise_unit foeb{6.05e6, btu_59};
constexpr precise_unit hartree{4.3597447222071e-18, J};
constexpr precise_unit hartree{4.3597447222060e-18, J};
constexpr precise_unit tonhour{3.5168528421, kWh};

constexpr precise_unit scf_mol{1.1953, mol};
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22 changes: 14 additions & 8 deletions units/units.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2212,14 +2212,15 @@ namespace constants {
constexpr precise_measurement H0{
69.8,
precise::km / precise::s / (precise::mega * precise::distance::parsec)};
/// constant values from https://physics.nist.gov/cgi-bin/cuu
/// Mass of an electron
constexpr precise_measurement me{9.1093837015e-31, precise::kg};
constexpr precise_measurement me{9.1093837139e-31, precise::kg};
/// Mass of a proton
constexpr precise_measurement mp{1.67262192369e-27, precise::kg};
constexpr precise_measurement mp{1.67262192595e-27, precise::kg};
/// Mass of a neutron
constexpr precise_measurement mn{1.67492749804e-27, precise::kg};
constexpr precise_measurement mn{1.67492750056e-27, precise::kg};
/// Bohr radius
constexpr precise_measurement a0{5.29177210903e-11, precise::m};
constexpr precise_measurement a0{5.29177210544e-11, precise::m};
/// Faraday's constant
constexpr precise_measurement F = Na * e;

Expand Down Expand Up @@ -2247,11 +2248,13 @@ namespace constants {
} // namespace planck
/// measurements related to an electron or atomic measurements
namespace atomic { // https://www.bipm.org/en/publications/si-brochure/table7.html
constexpr precise_measurement length{5.29177210903e-11, precise::m};
constexpr precise_measurement length = a0;
constexpr precise_measurement mass = me;
constexpr precise_measurement time{2.4188843265857e-17, precise::s};
constexpr precise_measurement charge = e;
constexpr precise_measurement energy{4.3597443419e-18, precise::J};
constexpr precise_measurement energy{
precise::energy::hartree.multiplier(),
precise::J};
constexpr precise_measurement action{
1.054571817e-34,
precise::J* precise::s};
Expand All @@ -2277,10 +2280,10 @@ namespace constants {
2.8e-40};
constexpr uncertain_measurement mp{
measurement_cast(constants::mp),
0.51e-36};
0.52e-36};
constexpr uncertain_measurement mn{
measurement_cast(constants::mn),
0.95e-36};
0.85e-36};
constexpr uncertain_measurement alpha{
measurement_cast(constants::alpha),
1.1e-12};
Expand All @@ -2299,6 +2302,9 @@ namespace constants {
constexpr uncertain_measurement H0{
measurement_cast(constants::H0),
1.7};
constexpr uncertain_measurement a0{
measurement_cast(constants::a0),
8.2e-21};
} // namespace uncertain
} // namespace constants

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