. Author manuscript; available in PMC: 2018 Feb 1.

Published in final edited form as: J Am Soc Mass Spectrom. 2016 Dec 2;28(2):323–331. doi: 10.1007/s13361-016-1525-7

Table 2.

Gibbs free energies (solution-phase) and energy differences (gas-phase) of the androsterone and trans-androsterone sodiated monomers, obtained at B3LYP-D3/6-31G(d) level. The differences are reported in kcal/mol and are with respect to the most stable sodiated monomer.

Binding mode	Gibbs Free Energy difference (Solution-Phase)	Energy difference (Gas-phase)
	Androsterone
Na⁺ binding at ketone	0.000	0.000
Na⁺ binding at hydroxyl	0.276	4.016
	trans-androsterone
Na⁺ binding at ketone	0.000	0.000
Na⁺ binding at hydroxyl	0.522	4.275