Elements, Atomic Radii and the Periodic Radii

search site | contact us

HOME

PRODUCTS

DOWNLOADS

SALES

SUPPORT

NEWS

Tutorials

Elements, Atomic Radii and the Periodic Table

Graphical Overview Table of Atomic Radii

The following table contains some of the atomic radius data used by CrystalMaker. This is a brief summary of a far more extensive body of work - please see the notes at the end of this page for more information.

Atomic Number	Element Symbol	Atomic Radius [Å]	Ionic Radius [Å]	Covalent Radius [Å]	Van-der-Waals Radius [Å]	"Crystal" Radius [Å]
1	H	0.53	0.25	0.37	1.20	0.10
2	He	0.31	0.31	0.32	1.40
3	Li	1.67	1.45	1.34	1.82	0.90
4	Be	1.12	1.05	0.90		0.41
5	B	0.87	0.85	0.82		0.25
6	C	0.67	0.70	0.77	1.70	0.29
7	N	0.56	0.65	0.75	1.55	0.30
8	O	0.48	0.60	0.73	1.52	1.21
9	F	0.42	0.50	0.71	1.47	1.19
10	Ne	0.38	0.38	0.69	1.54
11	Na	1.90	1.80	1.54	2.27	1.16
12	Mg	1.45	1.50	1.30	1.73	0.86
13	Al	1.18	1.25	1.18		0.53
14	Si	1.11	1.10	1.11	2.10	0.40
15	P	0.98	1.00	1.06	1.80	0.31
16	S	0.88	1.00	1.02	1.80	0.43
17	Cl	0.79	1.00	0.99	1.75	1.67
18	Ar	0.71	0.71	0.97	1.88
19	K	2.43	2.20	1.96	2.75	1.52
20	Ca	1.94	1.80	1.74		1.14
21	Sc	1.84	1.60	1.44		0.89
22	Ti	1.76	1.40	1.36		0.75
23	V	1.71	1.35	1.25		0.68
24	Cr	1.66	1.40	1.27		0.76
25	Mn	1.61	1.40	1.39		0.81
26	Fe	1.56	1.40	1.25		0.69
27	Co	1.52	1.35	1.26		0.54
28	Ni	1.49	1.35	1.21	1.63	0.70
29	Cu	1.45	1.35	1.38	1.40	0.71
30	Zn	1.42	1.35	1.31	1.39	0.74
31	Ga	1.36	1.30	1.26	1.87	0.76
32	Ge	1.25	1.25	1.22		0.53
33	As	1.14	1.15	1.19	1.85	0.72
34	Se	1.03	1.15	1.16	1.90	0.56
35	Br	0.94	1.15	1.14	1.85	1.82
36	Kr	0.88	0.88	1.10	2.02
37	Rb	2.65	2.35	2.11		1.66
38	Sr	2.19	2.00	1.92		1.32
39	Y	2.12	1.85	1.62		1.04
40	Zr	2.06	1.55	1.48		0.86
41	Nb	1.98	1.45	1.37		0.78
42	Mo	1.90	1.45	1.45		0.79
43	Tc	1.83	1.35	1.56		0.79
44	Ru	1.78	1.30	1.26		0.82
45	Rh	1.73	1.35	1.35		0.81
46	Pd	1.69	1.40	1.31	1.63	0.78
47	Ag	1.65	1.60	1.53	1.72	1.29
48	Cd	1.61	1.55	1.48	1.58	0.92
49	In	1.56	1.55	1.44	1.93	0.94
50	Sn	1.45	1.45	1.41	2.17	0.69
51	Sb	1.33	1.45	1.38		0.90
52	Te	1.23	1.40	1.35	2.06	1.11
53	I	1.15	1.40	1.33	1.98	2.06
54	Xe	1.08	1.08	1.30	2.16	0.62
55	Cs	2.98	2.60	2.25		1.81
56	Ba	2.53	2.15	1.98		1.49
57	La	1.95	1.95	1.69		1.36
58	Ce	1.85	1.85			1.15
59	Pr	2.47	1.85			1.32
60	Nd	2.06	1.85			1.30
61	Pm	2.05	1.85			1.28
62	Sm	2.38	1.85			1.10
63	Eu	2.31	1.85			1.31
64	Gd	2.33	1.80			1.08
65	Tb	2.25	1.75			1.18
66	Dy	2.28	1.75			1.05
67	Ho	2.26	1.75			1.04
68	Er	2.26	1.75			1.03
69	Tm	2.22	1.75			1.02
70	Yb	2.22	1.75			1.13
71	Lu	2.17	1.75	1.60		1.00
72	Hf	2.08	1.55	1.50		0.85
73	Ta	2.00	1.45	1.38		0.78
74	W	1.93	1.35	1.46		0.74
75	Re	1.88	1.35	1.59		0.77
76	Os	1.85	1.30	1.28		0.77
77	Ir	1.80	1.35	1.37		0.77
78	Pt	1.77	1.35	1.28	1.75	0.74
79	Au	1.74	1.35	1.44	1.66	1.51
80	Hg	1.71	1.50	1.49	1.55	0.83
81	Tl	1.56	1.90	1.48	1.96	1.03
82	Pb	1.54	1.80	1.47	2.02	1.49
83	Bi	1.43	1.60	1.46		1.17
84	Po	1.35	1.90			1.08
85	At	1.27	1.27			0.76
86	Rn	1.20	1.20	1.45
87	Fr					1.94
88	Ra		2.15			1.62
89	Ac	1.95	1.95			1.26
90	Th	1.80	1.80			1.19
91	Pa	1.80	1.80			1.09
92	U	1.75	1.75		1.86	0.87
93	Np	1.75	1.75
94	Pu	1.75	1.75			1.00
95	Am	1.75	1.75			1.12
96	Cm					1.11

About These Data

Atomic Radii: values are calculated from:

E Clementi, D L Raimondi, W P Reinhardt (1963) J Chem Phys. 38:2686.
Ionic Radii: these data are taken from an empirical system of unified atomic-ionic radii, which is suitable for describing anion-cation contacts in ionic structures. The data were derived by the comparison of bond lengths in over 1200 bond types in ionic, metallic, and covalent crystals and molecules by:

J C Slater (1964) J Chem Phys 41:3199

J C Slater (1965) Quantum Theory of Molecules and Solids. Symmetry and Bonds in Crystals. Vol 2. McGraw-Hill, New York.

Note that calculated data have been used for the following elements: He, Ne, Ar, Kr, Xe, At and Rn. These data were taken from:

E Clementi, D L Raimondi, W P Reinhardt (1963) J Chem Phys 38:2686
Covalent Radii: Data given here are taken from WebElements, copyright Mark Winter, University of Sheffield, UK.
Van-der-Waals Radii: Van der Waals radii are established from contact distances between non-bonding atoms in touching molecules or atoms. Most data here are from:

A Bondi (1964) J Phys Chem 68:441
"Crystal" Radii: These data are taken from Shannon & Prewitt's (S∓P) seminal work on "physical" ionic radii, as determined from measurements of real structures.

Note that in most cases S∓P quote different radii for the same element: the radii vary according to charge and coordination number. We have chosen the most-common charges (oxidation states) and coordination numbers. The details are given in the element text file after each data entry.

R D Shannon and C T Prewitt (1969) Acta Cryst. B25:925-946

R D Shannon (1976) Acta Cryst. A23:751-761