Table 3.

Database statistics for 11,981 biological unit proteins

	Minimum	Maximum	Mean	Median	SD	Skewnessa	Kurtosisb
Number of atoms	321	62495	3004	2994	3431	5.19	48.67
Number of residues	50	8290	383	265	441	5.27	50.71
Mean radius (Å)	59	5946	400	298	380	4.37	33.88
Net charge	–246	446	–5.68	–4	17.27	4.03	141.42
Dipole moment (Debye)	4	34460	639	452	977	14.36	333.26
Charge per atom	–0.038	0.031	–0.002	–0.002	0.005	0.28	3.90
Dipole per atom	0.000	4.486	0.300	0.246	0.248	2.82	20.16

^aThe symmetry of the distribution. The skewness of a normal Gaussian distribution is 0.

^bThe sharpness or flatness of the distribution. The kurtosis of a normal Gaussian distribution is 0.