H/D substitution was used to gain insight into the role of hydrogen bonding (HB) on the high-pressure stability of FOX-7. Raman measurements were performed on single crystals of deuterated FOX-7 (FOX-7-d(4)) compressed to 40 GPa. Comparison of present and previously published results for FOX-7 revealed that deuteration: (i) does not affect chemical stability to 40 GPa, (ii) removes spectral changes observed at 2 GPa, (iii) does not affect the pressure onset for the 4.5 GPa phase transition, and (iv) lifts the vibrational modes coupling. This work demonstrates that HB contributes selectively to different aspects of the high-pressure stability of FOX-7. (C) 2015 Elsevier B.V. All rights reserved.