. Author manuscript; available in PMC: 2020 Feb 13.

Published in final edited form as: J Am Chem Soc. 2019 Jan 29;141(6):2435–2445. doi: 10.1021/jacs.8b11474

Table 1.

Crystallographic Characterization of the Distribution of Na⁺ and K⁺ with Respect to a G-Quartet Plane from the PDB (See Also Figure 1 A)^a

	d (Å)	σ_⊥ (Å)	σ_∥ (Å)
K⁺	1.68	0.26	0.11
Na⁺	1.71	0.48	0.07

d is the average distance between the cation and the G-quartet plane, σ_⊥ and σ_∥ are the standard deviations along the perpendicular and parallel directions to the G-quartet plane (determined as the principal values of the distribution covariance tensor). A total of 232 G-quartets were found to directly coordinate at least one Na⁺, while 310 quartets were found coordinating K⁺.