Appendix A
Physical Constants and Conversion Factors
The values of physical constants and conversion factors listed in this appendix are
taken from NIST (https://physics.nist.gov/cuu/Constants/). According to the uncertainties quoted by NIST, all the digits here provided are correct.
Physical Constants, International System of Units (SI)
Name
Symbol Numerical value Units
Planck constant
h
6.626070 · 10 −34 J·s
Planck constant/2π
1.054572 · 10 −34 J·s
Bohr radius
a 0
0.529177 · 10 −10 m
Electron mass
m e 9.109384 · 10 −31 kg
Neutron mass
m n 1.674927 · 10 −27 kg
Proton mass
m p 1.672622 · 10 −27 kg
Atomic mass constant
m u 1.660539 · 10 −27 kg
Elementary charge
e
1.602177 · 10 −19 C
Electric constant
ε 0
8.854188 · 10 −12 F m −1
Speed of light in vacuo
c
2.99792458 · 10 8 m s −1
Avogadro constant
N A 6.022141 · 10 23
Boltzmann constant
K B 1.38065 · 10 −23 J K −1
Molar gas constant
R
8.31446
J mol −1 K −1
Energy Conversion Factors
From / to kJ/mol
kcal/mol
hartree
eV
cm −1
kJ/mol
1
0.239006
3.80880 · 10 −4
0.0103643
83.5935
kcal/mol 4.184000
1
1.59360 · 10 −3
0.0433641
349.755
Hartree
2625.50
627.509
1
27.21139
2.194746 · 10 5
eV
96.4853
23.0605
0.03674932
1
8065.544
cm −1
0.0119627 2.859144 · 10 −3 4.556335 · 10 −6 1.239842 · 10 −4
1
© Springer International Publishing AG, part of Springer Nature 2018
M. Persico and G. Granucci, Photochemistry, Theoretical Chemistry
and Computational Modelling, https://doi.org/10.1007/978-3-319-89972-5
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