| Speed of light | c | 2.99792458 x 108 m/s |
| Elementary charge | e | 1.602177 x 10-19 C |
| Faraday constant | F=eNA | 9.6485 x 104 C/mol |
| Boltzmann constant | k | 1.38066 x 10-23 J/K |
| Gas constant | R=kNA | 8.31451 J/K/mol
8.20578 x10-2 dm3atm/K/mol 62.364 L Torr /K/mol |
| Planck constant | h
h/2Pi |
6.62608 x 10-34 J s
1.05457 x 10-34 J s |
| Avogadro constant | NA | 6.02214 x 10-23 mol-1 |
| Atomic mass unit | u | 1.66054 x 10-27 kg |
| Mass of electron | me | 9.10939 x 10-31 kg |
| Mass of proton | mp | 1.67262 x 10-27 kg |
| Mass of newtron | mn | 1.67493 x 10-27 kg |
| Vacuum permeability | u0 | 4 Pi x 10-7 J s2 C-2 m-1 |
| Vacuum permitivity | e0=1/c2u0
4 Pi e0 |
8.85419 x 10-12 J-1 C2 m-1
1.11265 x 10-10 J-1 C2 m-1 |
| Bohr magneton | uB=eh/2Pi/2me | 9.27402 x 10-24 J T-1 |
| Nuclear magneton | uN=eh/2Pi/2mp | 5.05079 x 10-27 J T-1 |
| Electron value | ge | 2.00232 |
| Bohr radius | a0 | 5.29177 x 10-11 m |
| Rydberg constant | R | 1.09737 x 105 cm-1 |
| Fine structure constant | a=u0e2c/2h | 7.29735 x 10-3 |
| Gravitational constant | G | 6.67259 x 10-11 N m2 kg-2 |
| Standard acceleration of free fall | g | 9.80665 ms-2 |
2. Useful Relations
| hc | 1.98645 x 10-23 J cm |
| hc/k | 1.43877 cm K |
| h/k | 4.79922 x 10-11 K Hz-1 |
| 8 Pi hc | 4.99249 x 10-24 J m s-2 |
3. Energy Conversion Factors
| J | erg | eV | cm-1 | hartree | kcal/mol | |
| 1 J = | 1 | 107 | 6.2415x1018 | 5.0340x1022 | 2.2937x1017 | 1.4393x1020 |
| 1 erg = | 10-7 | 1 | 6.2415x1011 | 5.0340x1015 | 2.2937x1010 | 1.4393x1013 |
| 1 eV = | 1.6022x10-19 | 1.6022x10-12 | 1 | 8065.5 | 3.6749x10-2 | 23.060 |
| 1 cm-1 = | 1.9865x10-23 | 1.9865x10-16 | 1.2398x10-4 | 1 | 4.5563x10-6 | 2.8591x10-3 |
| 1 hartree = | 4.3598x10-18 | 4.3598x10-11 | 27.212 | 219474.6 | 1 | 627.51 |
| 1 kcal/mol = | 6.9478x10-21 | 6.9478x10-14 | 4.3364x10-2 | 349.75 | 1.5936x10-3 | 1 |
4. Mathematical Constants
Pi = 3.14159265359
e = 2.71828182846