Cruz, Fernando J. A. L.Alavi, SamanMota, José P. B.2019-07-192019-07-192019-05-162472-3452PURE: 14055855PURE UUID: 80a387bb-6368-4e61-a72f-56aacf22d915Scopus: 85064130220WOS: 000468366300012http://www.scopus.com/inward/record.url?scp=85064130220&partnerID=8YFLogxKPOCI-01-0145-FEDER - 007265. RE-QUIMTE/BPD/004/2016.The thermodynamics of metastable empty sI-clathrate hydrates are probed over broad temperature and pressure ranges, 100 ≤ T (K) ≤ 220 and 1 ≤ p (bar) ≤ 5000, respectively, by large-scale simulations and compared with experimental data at 1 bar. The whole p-V-T surface obtained is fitted by the universal form of the Parsafar and Mason equation of state with an accuracy of 99.7-99.9%. Framework deformation brought about by the applied temperature follows a parabolic law, and there is a critical temperature above which the isobaric thermal expansion becomes negative, ranging from 194.7 K at 1 bar to 166.2 K at 5000 bar. That response to the applied (p, T) field is analyzed in terms of angle and distance descriptors of a classical tetrahedral structure and observed to occur essentially by means of angular alteration for (p, T) > (2000 bar, 200 K). The length of the hydrogen bonds responsible for framework integrity is insensitive to the thermodynamic conditions and its average value is r (O-H)=0.25 nm.117858291engEmpty clathrate hydratesisobaric expansivityisobaric heat capacitymolecular dynamicsp- V- T datastructurethermodynamicsGeochemistry and PetrologyAtmospheric ScienceSpace and Planetary Sciencejournal article10.1021/acsearthspacechem.9b00009https://www.scopus.com/pages/publications/85064130220