Plane angle

Plane angle radian rad The plane angle between two radii of a circle which cut off on the circumference an arc equal in length to the radius. 

B, abbret. (Eratarrungapunkt) freezing point. Ecket f. corner, angle edge (plane angle)... 

Flachen-satz, m. theorem of conservation of areas, -wert, m. surface value, -winkel, m. plane angle, -zahl,/. number of faces square number. 

Some non-SI units are explicitly permitted. They include for crystallographic statements 1 A = 1CT10 m = 100 pm and 1° = tt/ 180 rad (plane angle). The liter is also permitted (both abbreviations are official, L or 1) 1 L = 1 dm3. 

The PES is only a function of the shape of the molecule, as described by the internal coordinates (there are ZN — 6 of them for a non-collinear molecule of N atoms). There are many possible choices of internal coordinates, including atom-atom distances (bond lengths), bond angles, dihedral or out-of-plane angles, or some combination of these. However, the PES can be expressed solely in terms of the atom-atom distances (a result that follows from the group theory of functions like the PES which are invariant to rotation).48,49 For N atoms there are NCi = N(N — l)/2 such distances, which are easily calculated from the Cartesian coordinates. Rather than use these atom-atom distances, Rn, we actually use the reciprocal distances, Zn ... 

Time 2. Supplementary SI units Plane angle second radian s rad Duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of file ground state of the cesium-133 atom. The plane angle between two radii of a circle which cut off on file circumference an arc equal in length to the radius. 

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