Experimental and Theoretical Investigations of Terahertz Spectra of the Structural Isomers: Mannose and Galactose

Table 2

Calculated bond angles (°) and RMSD values of mannose and galactose compared to experimental X-ray values^a.

Mannose					Galactose
CASTEP		Gaussian	CASTEP		Gaussian
Bond angle	Exp.	PBE	PW91	B3LYP	Bond angle	Exp.	PBE	PW91	B3LYP
O1–C1–O5	105.60	106.28	106.82	108.25	O1–C2–O5	111.83	110.61	110.61	109.84
O1–C1–C2	115.70	113.76	113.94	111.16	O1–C2–C3	108.11	112.12	112.47	110.17
O5–C1–C2	111.00	109.66	110.06	110.72	C3–C2–O5	107.55	110.74	110.82	111.24
O2–C2–C1	106.30	108.50	108.59	106.63	C2–C3–C4	110.07	108.72	108.80	111.67
O2–C2–C3	112.20	112.50	112.54	110.62	C2–C3–O2	109.34	108.89	108.75	109.97
C1–C2–C3	107.60	108.53	109.06	111.88	O2–C3–C4	112.90	113.79	113.84	106.72
O3–C3–C4	111.80	111.28	111.87	111.45	C3–C4–C1	109.77	108.88	108.78	109.77
O3–C3–C2	107.60	109.58	108.78	107.04	C3–C4–O3	110.79	111.71	111.69	111.15
C4–C3–C2	112.90	112.12	112.36	111.13	O3–C4–C1	110.14	112.74	112.78	110.35
O4–C4–C3	106.20	107.02	106.82	105.92	C4–C1–C5	107.75	107.48	107.49	107.18
O4–C4–C5	111.80	111.00	111.27	113.37	C4–C1–O4	110.79	112.90	112.79	112.58
C3–C4–C5	110.90	110.08	109.34	109.02	O4–C1–C5	113.36	113.26	113.24	110.73
O5–C5–C4	111.70	111.46	110.86	108.63	C1–C5–O5	110.64	111.04	111.14	107.79
O5–C5–C6	107.00	105.89	106.71	105.56	C1–C5–C6	113.15	115.73	115.59	114.15
C4–C5–C6	111.50	112.61	113.04	114.44	O5–C5–C6	105.42	103.31	103.29	107.00
O6–C6–C5	110.80	111.54	112.35	111.30	C5–C6–O6	109.18	113.13	113.19	111.02
C5–O5–C1	112.20	113.43	112.76	114.44	C2–O5–C5	114.22	115.24	115.41	113.87
RMSD	—	1.168	1.179	2.219	RMSD	—	2.050	2.102	2.285

^aThe experimental values are taken from references [22, 23].