. Author manuscript; available in PMC: 2016 Jun 6.

Published in final edited form as: J Phys Chem B. 2015 Jun 10;119(25):8024–8036. doi: 10.1021/acs.jpcb.5b04647

Table 3.

Quantum chemical calculations (GIPAW) of ¹⁷O NMR parameters for crystalline amino acid monohydrates

Sample	Site	C_Q, MHz	η	δ_iso, ppm^†	Ω, ppm	κ

Arg	H₂O^x	8.254	0.82	27.18	55.895	−0.324
Arg	H₂O^x	8.248	0.78	28.55	54.648	−0.636

Asn	H₂Oⁿ	8.267	0.80	2.60	59.544	−0.33
Asn	H₂O^x	8.274	0.80	−1.35	54.359	−0.361

Asp	H₂O^x	8.326	0.82	0.27	53.868	−0.333

Cys	H₂O^x	8.252	0.75	37.98	32.61	0.235
	CO^x	8.508	0.06	348.48	509.477	−0.39
	C-OH^x	−7.559	0.26	201.21	366.088	−0.085

Gly-Gly	H₂Oⁿ	7.248	0.98	15.44	49.657	−0.478
	H₂O^x	7.367	0.87	30.66	53.68	−0.604
	COⁿ	8.558	0.05	341.44	588.503	−0.55
	CO^x	8.553	0.02	342.31	582.602	−0.509
	C-OHⁿ	−7.582	0.25	178.06	241.001	0.947
	C-OH^x	−7.549	0.24	185.33	244.051	0.947

Gly-Gln	H₂O^x	7.748	0.87	7.07	50.321	−0.448

His	H₂Oⁿ	8.620	0.73	14.24	49.961	0.306
His	H₂O^x	8.544	0.72	14.80	50.592	0.235

NB: All crystal structures underwent a H geometry optimization step to reduce the overall energy/symmetrized forces, x – x-ray and n – neutron determined crystal structures,

^†

referenced using σ_ref of 275.69 ppm.