Share on Facebook Share on Twitter Email
Answers.com

Hartree units

 
Sci-Tech Dictionary: Hartree units
Home > Library > Science > Sci-Tech Dictionary
(′här·trē ′yü·nəts)

(atomic physics) A system of units in which the unit of angular momentum is Planck's constant divided by 2π, the unit of mass is the mass of the electron, and the unit of charge is the charge of the electron. Also known as atomic units.

Search unanswered questions...

Enter a question here...
Search: All sources Community Q&A Reference topics

Measures and Units: atomic unit
Top
Home > Library > Science > Measures and Units

physics. Symbol a.u. Any one of the coherent set of units based on the Bohr radius plus other natural sub-atomic units introduced by Hartree in 1927.
[Hartree D. R. Proc. Camb. Phil. Soc. Vol. 24, 89 (1927)] (Compare natural unit.) Named generically atomic unit of action, etc. (and earlier sometimes the Hartree unit of action, etc., though that personal name is used now to mean the atomic unit of energy), the members and their current values (with 108 times the relative standard uncertainty appended to each)
[Mohr P. J., Taylor B. N. CODATA Recommended Values of the Fundamental Physical Constants: 2002 (to be published)]
[Mohr P. J., Taylor B. N. Rev. Mod. Phys. Vol. 72:351-495 (2000)]
[Mohr P. Phys. Today Vol. 53:7, 11-16 (2000)]
[For latest recommended values, see http://physics.nist.gov/cuu/Constants/index.html] of the derived units are shown in Table 4.

Table 4
Base units: atomic unit of
actionℏthe Planck constant over 2 π
chargeethe elementary charge
lengtha0 Bohr radius
massme electron mass
Derived units: atomic unit of
charge densitye/a031.081 202 317(93) × 1012 C·m-38.6
currente·Eh/ℏ6.623 617 82(57) × 10-3 A8.5
electric dipole momente·a08.478 353 09(73) × 10-30 C·m8.6
electric fieldEh/e·a05.142 206 42(44) × 1011 V·m-18.6
electric field gradientEh/e·a029.717 361 82(83) × 1021 V·m-28.6
electric polarizabilitye2·a02/Eh1.648 777 274(16) × 10-41 C2·m2·J-11.0
electric potentialEh/e27.211 384 5(23) × 101 V8.5
electr. quadrupole momente·a024.486 551 24(39) × 10-40 C·m28.6
energy (Hartree)Eh = me·e4/ℏ24.359 744 17(75) × 10-18 J17
forceEh/a08.238 722 5(14) × 10-8 N17
magnetic dipole momente·ℏ/me1.854 801 90(16) × 10-23 J·T-18.6
magnetic flux densityℏ/e·a022.350 517 42(20) × 105 T8.6
magnetizabilitye2·a02/me7.891 036 60(13) × 10-29 J·T-21.7
momentumℏ/a01.992 851 66(34) × 10-24 kg·m·s-117
permittivitye2/a0·Eh1.112 650 056~ × 10-10 F·m-1(exact)
timeℏ/Eh2.418 884 326 505(16) × 10-17 s0.0*
velocity (or speed)a0·Eh/ℏ2.187 691 263 3(73) × 106 m·s-10.33
The asterisked figure is 0.000 66.

 
 

 

Copyrights:

Sci-Tech Dictionary. McGraw-Hill Dictionary of Scientific and Technical Terms. Copyright © 2003, 1994, 1989, 1984, 1978, 1976, 1974 by McGraw-Hill Companies, Inc. All rights reserved.  Read more
Measures and Units. A Dictionary of Weights, Measures, and Units. Copyright © Donald Fenna 2002, 2004. All rights reserved.  Read more