title: Ab Initio Studies on the Clathrate Hydrates of Some Nitrogen- and Sulfur-Containing Gases.
abstract: Ab initio calculations are performed to investigate the host-guest interactions and multiple occupancies of some sulfur- (H2S, CS2) and nitrogen-containing (N2, NO, and NH3) molecules in dodecahedral, tetrakaidecahedral, and hexakaidecahedral water cages in this work. Five functionals in the framework of density functional theory are compared, and the M06-2X method appears to be the best to predict the binding energies as well as the geometries. Results show that N2and NO molecules are more stable in the 51264cage, while NH3and H2S prefer to stabilize in the 51262cage. This suggests that the sI hydrates of NH3and H2S exhibit higher stability than the sII structures and that sII NO hydrate is more stable than sI NO hydrate. N2is found to be more stable in type II structure with single occupancy and to form type I hydrate with multiple occupancy, which is consistent with the experimental observations. As to the guest molecule CS2, it may undergo severe structural deformation in the 512and 51262cage. For multiple occupancies, the 512, 51262, and 51264water cages can trap up to two N2molecules, and the 51264water cage can accommodate two H2S molecules. This work is expected to provide new insight into the formation mechanism of clathrate hydrates for atmospherically important molecules.
authors.affiliation: School of Chemistry and Materials Science, Heilongjiang University , Harbin, Heilongjiang 150080, P. R. China.
authors.forename: Ningru
authors.initials: N
authors.lastname: Sun
authors.affiliation: School of Chemistry and Materials Science, Heilongjiang University , Harbin, Heilongjiang 150080, P. R. China.
authors.forename: Zewen
authors.initials: Z
authors.lastname: Li
authors.affiliation: Engineering Laboratory of Specialty Fibers and Nuclear Energy Materials, Ningbo Institute of Industrial Technology, Chinese Academy of Sciences , Ningbo, Zhejiang 315201, P. R. China.
authors.forename: Nianxiang
authors.initials: N
authors.lastname: Qiu
authors.affiliation: National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science , Beijing 100190, P. R. China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Yu
authors.affiliation: Engineering Laboratory of Specialty Fibers and Nuclear Energy Materials, Ningbo Institute of Industrial Technology, Chinese Academy of Sciences , Ningbo, Zhejiang 315201, P. R. China.
authors.forename: Xuran
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Power and Energy Engineering, Harbin Engineering University , Harbin, Heilongjiang 150001, P. R. China.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Power and Energy Engineering, Harbin Engineering University , Harbin, Heilongjiang 150001, P. R. China.
authors.forename: Longbin
authors.initials: L
authors.lastname: Yang
authors.affiliation: Engineering Laboratory of Specialty Fibers and Nuclear Energy Materials, Ningbo Institute of Industrial Technology, Chinese Academy of Sciences , Ningbo, Zhejiang 315201, P. R. China.
authors.forename: Kan
authors.initials: K
authors.lastname: Luo
authors.affiliation: Engineering Laboratory of Specialty Fibers and Nuclear Energy Materials, Ningbo Institute of Industrial Technology, Chinese Academy of Sciences , Ningbo, Zhejiang 315201, P. R. China.
authors.forename: Qing
authors.identifier: http://orcid.org/0000-0001-7083-9416
authors.initials: Q
authors.lastname: Huang
authors.affiliation: Engineering Laboratory of Specialty Fibers and Nuclear Energy Materials, Ningbo Institute of Industrial Technology, Chinese Academy of Sciences , Ningbo, Zhejiang 315201, P. R. China.
authors.forename: Shiyu
authors.identifier: http://orcid.org/0000-0001-6707-3915
authors.initials: S
authors.lastname: Du