Table 4: Calculated hydrogen-bond distances ( , Å), hydrogen-bond angles ( , degree), dipole moment ( , debye) for DPG molecule and DPG + water complex ( = 1, 2, 3), DPG dimer, and water dimer using 6-31++G(d,p) basis set and various methods.

SystemParametersMethods
MP2WB97XDB3LYP
DFTD
MO62XMO6B3LYPHF

DPGD5.014.474.464.404.304.434.69

DPG + 1 water complex (GD) ,
O24...H21
1.931.901.881.911.931.932.05
,
O24 H21–O20
178.60176.25175.19176.23164.79174.44177.44
D5.484.674.625.235.754.615.00

DPG + 1 water complex (WD) ,
O22 H24
1.901.881.861.911.911.902.03
,
O22 H24–O25
162.78166.07161.8151.04155.18167.98171.36
D4.034.173.682.993.174.294.99

DPG + 2 water complex ,
O22 H24
1.901.891.861.921.911.902.03
,
O20 H28
1.901.891.861.921.911.902.03
,
O22 H24–O25
162.54161.59161.55149.65154.93167.89170.64
,
O20 H28–O27
162.54161.60161.68149.66154.94167.88170.64
D4.654.214.182.453.295.476.04

DPG dimer ,
O43 H23
1.891.871.901.911.912.04
,
O43 H23–O22
171.89167.63170.67167.46171.92172.87
D7.095.836.937.045.195.65