Atomic units: Difference between revisions

From Citizendium
Jump to navigation Jump to search
imported>John R. Brews
(add charge to table)
imported>John R. Brews
(→‎Base units: notation)
Line 44: Line 44:
|2.418 884 326 505(16) × 10<sup>−17</sup> s
|2.418 884 326 505(16) × 10<sup>−17</sup> s
|-
|-
|[[Reduced Planck constant]]
|Reduced [[Planck constant]]
|'''ℏ'''
|'''ℏ'''
|[[action]]
|[[action]]
Line 53: Line 53:
|[[energy]]
|[[energy]]
|4.359 744 17(75)  × 10<sup>−18</sup> J
|4.359 744 17(75)  × 10<sup>−18</sup> J
|-
|-
|[[a.u. velocity]]
|'''v<sub>B</sub>≡αc'''
|[[velocity]]
|2.187 691 2633(73) × 10<sup>6</sup> m/s
|-
|-
|}
|}
Here, ''c'' = [[speed of light]] and ''&alpha;'' = [[fine structure constant]].


==Notes==
==Notes==
<references/>
<references/>

Revision as of 12:06, 10 March 2011

This article is developing and not approved.
Main Article
Discussion
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
 
This editable Main Article is under development and subject to a disclaimer.

The atomic units, abbreviated a.u. is a set of units used in atomic calculations.[1][2]

Base units

Atomic base units [2]
Name Symbol Quantity Value in SI units
elementary charge e charge 1.602 176 53(14) × 10−19 C
Bohr radius (bohr) a0 length 0.529 177 2108(18) × 10−10 m
electron mass me mass 9.109 3826(16) × 10−31 kg
Reduced period of first Bohr orbit ℏ/Eh time 2.418 884 326 505(16) × 10−17 s
Reduced Planck constant action 1.054 571 68(18) × 10−34 Js
Hartree energy (hartree) Eh energy 4.359 744 17(75) × 10−18 J
a.u. velocity vB≡αc velocity 2.187 691 2633(73) × 106 m/s

Here, c = speed of light and α = fine structure constant.

Notes

  1. For an introduction, see Gordon W. F. Drake (2006). “§1.2 Atomic units”, Springer handbook of atomic, molecular, and optical physics, Volume 1, 2nd ed. Springer, p. 6. ISBN 038720802X. 
  2. 2.0 2.1 Tabulated values from Barry N. Taylor (2008). International System of Units (SI), Revised 2008 ed. DIANE Publishing, Table 7, p.33. ISBN 1437915582.