The dispersion of the H-bond pair volume DeltaV over the decoupled OD and coupled OH-stretching contours from HDO in H2O was determined from Raman intensities at pressures to 9700 bar at 301 K. The dispersion of DeltaV was determined from -RT[partial derivative ln(I-i/I-REF)/partial derivativeP](T) versus omega (in cm(-1)), where i refers to omega's over the stretching contours and I-REF refers to the reference intensity at the isosbestic frequency. The maximum H-bond pair volume (defined for breakage) is 1.4+/-0.1 cm(3)/mol H-bond, which corresponds to the volume difference between a large dispersion maximum at 2675 cm(-1) (near the OD stretch omega of HDO in dense supercritical water) and a large, broad minimum centered near 2375 cm(-1) (just below the OD stretch omega of HDO in lda ice). The average is 0.71+/-0.10 cm(3)/mol H-bond. Other minima near 2625 cm(-1) (OD) and 3550 cm(-1) (OH) refers to bent H-bonds whose angles are approximate to150 deg. Isothermal pressurization of water lowers the molal volume by decreasing the concentration of long, weak H-bonds, and increasing the concentrations of bent H-bonds and short, strong, linear H-bonds. Such bending, shortening, and strengthening produces freezing to ice VI near 10 kbar at 301 K. The isobaric temperature derivative of the maximum H-bond volume is (partial derivativeDeltaV/partial derivativeT)(P)less than or equal to(2-5)x10(-3) cm(3)/deg mol H-bond. The OH enthalpy dispersion curve for saturated NaBF4 in water, yields a large maximum at 3530-3540 cm(-1) indicating that BF4- interacts preferentially with the dangling or "free" OH groups of water thus producing weak, strongly bent H-bonds having angles similar to those of the 3550 cm(-1) high-pressure H-bond bending feature. (C) 2004 American Institute of Physics.