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Elem Purdue Indiana Oxford York Stockholm Cambridge F&M CRC
H 37 30 30 28 32 23 37 46
Li 123 68 157 152
Be 89 106 116 35 125 114
B 88 83 90 79 83 90 97
C 77 77 77 77 77 68 77 77
N 70 70 70 70 70 68 75 71
O 66 66 66 66 66 68 73 60
F 64 64 64 64 61 64 71
Na 157 97 191 186
Mg 136 110 160 160
Al 125 118 135 140 143
Si 117 109 117 117 109 120 118 117
P 110 109 110 110 110 105 110 109
S 104 105 104 104 104 102 102 106
Cl 99 99 99 100 99 99 107
[from Indiana]
A.1 Carbon-based Covalent Radii
A.1.1 Single bond radii (pm)
Element H
Radius* 29.9
Element Be B C N O F
Radius 106 83.0 76.7 70.2 65.9 61.9
Source b a a a a a
Element Al Si P(III) S(II) Cl
Radius 118 109.0 108.8 105.2 102.3
Source b a a a a
Element Ga Ge As(III) Se(II) Br
Radius 125 122 119.6 120.3 119.9
Source b b a a a
Element In Sn Sb(III) Te(II) I
Radius 141 139 137 139.1 139.5
Source b b b a a
* The quoted radius for H applies to the actual position of the H-nucleus, as determined by neutron diffraction. With X-ray diffraction, the observed position of the H-atom is the centre of gravity of its electron cloud, which lies about 10 pm closer to the attached atom. This gives an apparent H-atom radius close to 20 pm.
Sources:
* a: From tabulations and averages of C(sp3)-X distances in Allen, F.H., Kennard, O., Watson, D.G., Brammer, L., Orpen, A.G., & Taylor, R. (1987) J.Chem. Soc. Perkin II, p. S1, subtracting 76.7pm for the radius of carbon.
* b: From individual CH3-X distances, again subtracting 76.7pm.
A.1.2 Multiple bond radii (pm)
Element C N O
Single 76.7 70.2 65.9
Double 66.1 61.8 54.9
Triple 59.1 54.5
Source:
* Allen et al. (1987), as section A.1.1
A.2 Van der Waals radii
Element N O F
Radius 155 152 147
Element Si P S Cl
Radius 210 180 180 175
Element Ge As Se Br
Radius 195 185 190 185
Element Sn Sb Te I Xe*
Radius 210 205 206 198 200
Element Bi
Radius 215
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