气体水合物分子间相互作用及其分解行为的理论研究
|
摘要
气体水合物在能源、环境领域有着不可限量的重要作用,尤其是称为“可燃冰”的甲烷水合物,以及储氢潜力巨大的氢气水合物。据估计,地球上可燃冰矿藏中有机碳的含量是所有化石能源中有机碳含量的两倍,被认为是重要的后续能源。此外,二氧化碳可以以水合物的形式封存在海底,减少温室效应。因此,世界各国正在加快加强关于气体水合物的研究,以期在可燃冰矿藏的开采、氢气的储藏及二氧化碳的封存方面占据国际领先地位。
关于气体水合物的计算研究工作中,前人所采用的计算方法不能准确描述分子间的非共价键相互作用。随着非共价键体系的重要性提高,近年来发展了一些考虑了长程色散作用的密度泛函方法,我们通过以高精度的从头算作为基准,系统地评估了这些方法用来描述甲烷水合物体系中分子间相互作用的能力。在这些被评估的DFT方法中,ωB97X-D、 X3LYP、 B3LYP、M06-2X及B97-D描述水分子间的氢键能极其优秀；ωB97X-D、 M06-2X及B97-D是描述甲烷分子和水笼子间的范德瓦尔斯相互作用最好的方法。综合考虑计算精度和成本,考虑了BSSE校正的ωB97X-D/6-311++G(2d,2p)和M06-2X/6-311++G(2d,2p)为描述甲烷水合物体系分子间非共价键相互作用最好的计算方案。另外,未考虑BSSE校正的B97-D/6-311++G(2d,2p)也是一个合理的选择。
二氧化碳水合物的很多重要应用与其分解过程密切相关,但是关于二氧化碳水合物的分解行为缺乏研究,前人还没有确定其原子分子水平上的分解机制。我们通过分子动力学模拟结合第一性原理计算,模拟了二氧化碳水合物的分解行为,并与甲烷水合物和氢气水合物的分解过程做了对比研究。然后通过客体分子从水笼子中向外扩散所需克服的能垒的计算,揭示了隐藏在不同气体水合物分解行为背后的物理原因。二氧化碳水合物分解的微观机制可概括为：首先,随着温度升高,水分子扩散加剧,构成Ⅰ型水合物的有序晶体骨架由于水分子扩散发生扭曲变形,直至破裂开口；然后,封存在水笼孔穴中的二氧化碳分子被释放,以小气泡的形式分散在水溶液中；最后,水合物的有序晶体骨架彻底被破坏,二氧化碳分子在水溶液中聚集成一个大气泡。而且,二氧化碳水合物的解离行为不仅和总占据率有关,还依赖于客体分子占据的特定的水笼孔穴的类型,小笼子被占据的越多越容易解离。此外,由于客体分子较高的扩散能垒,导致二氧化碳水合物和甲烷水合物的微观分解行为相似,都是水分子氢键网络骨架先破裂,然后客体分子被释放；但是,对于氢气水合物,由于氢气较低的扩散能垒,氢气分子首先在水分子氢键网络骨架间自由扩散,导致出现空的水笼孔穴,由于空笼不稳定,使氢键骨架局部发生破坏,然后氢气分子被释放,最终有序的晶体骨架彻底被破坏。
Gas hydrates have definitely promising role in energy and environment field, especially for methane hydrate which called "fired ice" and hydrogen hydrate which has huge potential for storing hydrogen. It is estimated that the amount of organic carbon in fired ice deposits on earth is twice as much as which included in the fossil energy, so fired ice is considered as backup energy in future. Moreover, carbon dioxide can be sequestrated under the ocean floor in the form of carbon dioxide hydrates to reduce the greenhouse effect. Because of that, many governments are required to strengthen the studies on gas hydrates, so as to be in leading position in the technology for exploiting fired ice deposits, storing hydrogen in the form of hydrogen hydrate, and sequestrating carbon dioxide in the form of carbon dioxide hydrate in the world.
The computational methods employed in previous papers on gas hydrates cannot give accurate description for the intermolecular non-covalent interaction in gas hydrates. As the importance of non-covalent interacting system improving, many DFT methods added long-range dispersion correction are developed in recent years. Compared with the benchmark results calculated at the high-level ab initio methods, we assessed the ability of twenty DFT methods to describe the intermolecular interaction in methane hydrate. Among the evaluated DFT methods, the performance of coB97X-D, X3LYP, B3LYP, M06-2X and B97-D to describe the hydrogen bonding energy between water molecules is excellent; at the same time, coB97X-D, M06-2X and B97-D is the best methods to describe the van der Waals interaction between methane molecule and water cage. Considering both computational precision and cost, we recommended both ωB97X-D/6-311++G(2d,2p) and M06-2X/6-311++G(2d,2p) with BSSE correction is the best calculating scheme to describe the intermolecular interaction in methane hydrate; in addition, B97-D/6-311++G(2d,2p) without BSSE correction is also a reasonable choice.
Many important applications of carbon dioxide hydrate are closely related to the dissociation process of carbon dioxide hydrate, but there are only few studies on the dissociation behavior of carbon dioxide hydrate, and the microscopic dissociation mechanism of carbon dioxide hydrate has not been fixed until now. Through molecular dynamic simulation and first-principle calculation, we simulated the dissociation behavior of carbon dioxide hydrate, methane hydrate and hydrogen hydrate. Then based on the barrier of guest molecules diffusing from the inner of the water cage to outer, we revealed the physical origin under the dissociation behavior. We find the dissociation mechanism of carbon dioxide hydrate can be summarized as three steps:firstly, as the temperature increasing, the diffusion behavior of water molecules become severe, and the crystal structure of carbon dioxide hydrate distorted and even damaged as the water molecules diffusing; secondly, the carbon dioxide molecules trapped in the water cavities are released through the small opening and dispersed in the water solution in the form of small bubble; finally, the crystal structure of carbon dioxide hydrate is completely destroyed, and the small bubbles gather into a large bubble in the water solution. Moreover, the dissociation behavior of carbon dioxide hydrate not only depends on the overall occupancy of guest molecules, but also is related to the specific type of water cavity occupied by guest molecules; the more the small water cavities is occupied, the easier the dissociation is. In addition, as the higher diffusion barrier of guest molecules, the dissociation behavior of carbon dioxide is similar to that of methane hydrate; both the hydrogen bonding clathrate skeleton of water molecules firstly damaged, and then the trapped guest molecules are released. But for hydrogen hydrate, as the lower diffusion barrier of hydrogen molecules, the endohedral hydrogen molecules firstly diffuse freely in the structure framework of hydrate, and the local crystal structure is damaged as the unsteady empty water cavities generated by the hydrogen molecules diffusion, and then the trapped hydrogen molecules are released through the small openings, finally the regular crystal structure of hydrate is completely destroyed.
关于气体水合物的计算研究工作中,前人所采用的计算方法不能准确描述分子间的非共价键相互作用。随着非共价键体系的重要性提高,近年来发展了一些考虑了长程色散作用的密度泛函方法,我们通过以高精度的从头算作为基准,系统地评估了这些方法用来描述甲烷水合物体系中分子间相互作用的能力。在这些被评估的DFT方法中,ωB97X-D、 X3LYP、 B3LYP、M06-2X及B97-D描述水分子间的氢键能极其优秀；ωB97X-D、 M06-2X及B97-D是描述甲烷分子和水笼子间的范德瓦尔斯相互作用最好的方法。综合考虑计算精度和成本,考虑了BSSE校正的ωB97X-D/6-311++G(2d,2p)和M06-2X/6-311++G(2d,2p)为描述甲烷水合物体系分子间非共价键相互作用最好的计算方案。另外,未考虑BSSE校正的B97-D/6-311++G(2d,2p)也是一个合理的选择。
二氧化碳水合物的很多重要应用与其分解过程密切相关,但是关于二氧化碳水合物的分解行为缺乏研究,前人还没有确定其原子分子水平上的分解机制。我们通过分子动力学模拟结合第一性原理计算,模拟了二氧化碳水合物的分解行为,并与甲烷水合物和氢气水合物的分解过程做了对比研究。然后通过客体分子从水笼子中向外扩散所需克服的能垒的计算,揭示了隐藏在不同气体水合物分解行为背后的物理原因。二氧化碳水合物分解的微观机制可概括为：首先,随着温度升高,水分子扩散加剧,构成Ⅰ型水合物的有序晶体骨架由于水分子扩散发生扭曲变形,直至破裂开口；然后,封存在水笼孔穴中的二氧化碳分子被释放,以小气泡的形式分散在水溶液中；最后,水合物的有序晶体骨架彻底被破坏,二氧化碳分子在水溶液中聚集成一个大气泡。而且,二氧化碳水合物的解离行为不仅和总占据率有关,还依赖于客体分子占据的特定的水笼孔穴的类型,小笼子被占据的越多越容易解离。此外,由于客体分子较高的扩散能垒,导致二氧化碳水合物和甲烷水合物的微观分解行为相似,都是水分子氢键网络骨架先破裂,然后客体分子被释放；但是,对于氢气水合物,由于氢气较低的扩散能垒,氢气分子首先在水分子氢键网络骨架间自由扩散,导致出现空的水笼孔穴,由于空笼不稳定,使氢键骨架局部发生破坏,然后氢气分子被释放,最终有序的晶体骨架彻底被破坏。
Gas hydrates have definitely promising role in energy and environment field, especially for methane hydrate which called "fired ice" and hydrogen hydrate which has huge potential for storing hydrogen. It is estimated that the amount of organic carbon in fired ice deposits on earth is twice as much as which included in the fossil energy, so fired ice is considered as backup energy in future. Moreover, carbon dioxide can be sequestrated under the ocean floor in the form of carbon dioxide hydrates to reduce the greenhouse effect. Because of that, many governments are required to strengthen the studies on gas hydrates, so as to be in leading position in the technology for exploiting fired ice deposits, storing hydrogen in the form of hydrogen hydrate, and sequestrating carbon dioxide in the form of carbon dioxide hydrate in the world.
The computational methods employed in previous papers on gas hydrates cannot give accurate description for the intermolecular non-covalent interaction in gas hydrates. As the importance of non-covalent interacting system improving, many DFT methods added long-range dispersion correction are developed in recent years. Compared with the benchmark results calculated at the high-level ab initio methods, we assessed the ability of twenty DFT methods to describe the intermolecular interaction in methane hydrate. Among the evaluated DFT methods, the performance of coB97X-D, X3LYP, B3LYP, M06-2X and B97-D to describe the hydrogen bonding energy between water molecules is excellent; at the same time, coB97X-D, M06-2X and B97-D is the best methods to describe the van der Waals interaction between methane molecule and water cage. Considering both computational precision and cost, we recommended both ωB97X-D/6-311++G(2d,2p) and M06-2X/6-311++G(2d,2p) with BSSE correction is the best calculating scheme to describe the intermolecular interaction in methane hydrate; in addition, B97-D/6-311++G(2d,2p) without BSSE correction is also a reasonable choice.
Many important applications of carbon dioxide hydrate are closely related to the dissociation process of carbon dioxide hydrate, but there are only few studies on the dissociation behavior of carbon dioxide hydrate, and the microscopic dissociation mechanism of carbon dioxide hydrate has not been fixed until now. Through molecular dynamic simulation and first-principle calculation, we simulated the dissociation behavior of carbon dioxide hydrate, methane hydrate and hydrogen hydrate. Then based on the barrier of guest molecules diffusing from the inner of the water cage to outer, we revealed the physical origin under the dissociation behavior. We find the dissociation mechanism of carbon dioxide hydrate can be summarized as three steps:firstly, as the temperature increasing, the diffusion behavior of water molecules become severe, and the crystal structure of carbon dioxide hydrate distorted and even damaged as the water molecules diffusing; secondly, the carbon dioxide molecules trapped in the water cavities are released through the small opening and dispersed in the water solution in the form of small bubble; finally, the crystal structure of carbon dioxide hydrate is completely destroyed, and the small bubbles gather into a large bubble in the water solution. Moreover, the dissociation behavior of carbon dioxide hydrate not only depends on the overall occupancy of guest molecules, but also is related to the specific type of water cavity occupied by guest molecules; the more the small water cavities is occupied, the easier the dissociation is. In addition, as the higher diffusion barrier of guest molecules, the dissociation behavior of carbon dioxide is similar to that of methane hydrate; both the hydrogen bonding clathrate skeleton of water molecules firstly damaged, and then the trapped guest molecules are released. But for hydrogen hydrate, as the lower diffusion barrier of hydrogen molecules, the endohedral hydrogen molecules firstly diffuse freely in the structure framework of hydrate, and the local crystal structure is damaged as the unsteady empty water cavities generated by the hydrogen molecules diffusion, and then the trapped hydrogen molecules are released through the small openings, finally the regular crystal structure of hydrate is completely destroyed.
引文
[1]SLOAN E D, KOH C A. Clathrate Hydrates of Natural Gases [M]. Third ed. Boca Raton:CRC Press/Taylor&Francis Group,2008.
[2]陈光进,孙长宇,马庆兰.气体水合物科学与技术[M].北京：化学工业出版社,2007.
[3]周怀阳,彭小彤,叶瑛.天然气水合物[M].北京：海洋出版社,2000.
[4]SLOAN E D. Fundamental principles and applications of natural gas hydrates [J]. Nature,2003, 426(6964):353-359.
[5]SUM A K, KOH C A, SLOAN E D. Clathrate Hydrates:From Laboratory Science to Engineering Practice [J]. Industrial& Engineering Chemistry Research,2009,48(16):7457-7465.
[6]KOH C A, SUM A K, SLOAN E D. Gas hydrates:Unlocking the energy from icy cages [J]. Journal of Applied Physics,2009,106(6):061101.
[7]VOS W L, FINGER L W, HEMLEY R J, et al. Novel H2-H2O clathrates at high pressures [J]. Physical Review Letters,1993,71(19):3150-3153.
[8]FLORUSSE L J, PETERS C J, SCHOONMAN J, et al. Stable low-pressure hydrogen clusters stored in a binary clathrate hydrate [J]. Science,2004,306(5695):469-471.
[9]UDACHIN K A, RATCLIFFE C I, RIPMEESTER J A. Structure, composition, and thermal expansion of CO2 hydrate from single crystal X-ray diffraction measurements [J]. Journal of Physical Chemistry B,2001,105(19):4200-4204.
[10]UCHIDA T, TAKEYA S, KAMATA Y, et al. Spectroscopic observations and thermodynamic calculations on clathrate hydrates of mixed gas containing methane and ethane:Determination of structure, composition and cage occupancy [J]. Journal of Physical Chemistry B,2002,106(48):12426-12431.
[11]UCHIDA T, TAKAGI A, KAWABATA J, et al. Raman spectroscopic analyses on the growth process of CO2 hydrates [J]. Energy Conversion and Management,1995,36(6-9):547-550.
[12]SUSILO R, RIPMEESTER J A, ENGLEZOS P. Characterization of gas hydrates with PXRD, DSC, NMR, and Raman spectroscopy [J]. Chemical Engineering Science,2007,62(15):3930-3939.
[13]SUM A K, BURRUSS R C, SLOAN E D. Measurement of clathrate hydrates via Raman spectroscopy [J]. Journal of Physical Chemistry B,1997,101(38):7371-7377.
[14]SUBRAMANIAN S, SLOAN E D. Trends in vibrational frequencies of guests trapped in clathrate hydrate cages [J]. Journal of Physical Chemistry B,2002,106(17):4348-4355.
[15]SUBRAMANIAN S, KINI R A, DEC S F, et al. Evidence of structure II hydrate formation from methane plus ethane mixtures [J]. Chemical Engineering Science,2000,55(11):1981-1999.
[16]RAWN C J, RONDINONE A J, CHAKOUMAKOS B C, et al. Neutron powder diffraction studies as a function of temperature of structure II hydrate formed from propane [J]. Canadian Journal of Physics, 2003,81(1-2):431-438.
[17]KUMAR R, LANG S, ENGLEZOS P, et al. Application of the ATR-IR Spectroscopic Technique to the Characterization of Hydrates Formed by CO2, CO2/H2 and CO2/H2/C3H8 [J]. Journal of Physical Chemistry A,2009,113(22):6308-6313.
[18]GUTT C, ASMUSSEN B, PRESS W, et al. The structure of deuterated methane-hydrate [J]. Journal of Chemical Physics,2000,113(11):4713-4721.
[19]UDACHIN K A, I. R C, A. R J. Single Crystal Diffraction Studies of Structure I, II and H Hydrates: Structure, Cage Occupancy and Composition [J]. Journal of Supramolecular Chemistry,2002,2:405-408.
[20]KIRCHNER M T, BOESE R, BILLUPS W E, et al. Gas hydrate single-crystal structure analyses [J]. Journal of the American Chemical Society,2004,126(30):9407-9412.
[21]GUPTA A, DEC S F, KOH C A, et al. NMR investigation of methane hydrate dissociation [J]. Journal of Physical Chemistry C,2007,111(5):2341-2346.
[22]CHOU I M, SHARMA A, BURRUSS R C, et al. Transformations in methane hydrates [J]. Proceedings of the National Academy of Sciences of the United States of America,2000,97(25): 13484-13487.
[23]CHRISTIANSEN R L, SLOAN E D. Mechanisms and Kinetics of Hydrate Formation [M]//SLOAN E D, HAPPEL J, HNATOW M A. International Conference on Natural Gas Hydrates.1994:283-305.
[24]SLOAN E D, FLEYFEL F. A molecular mechanism for gas hydrate nucleation from ice [J]. Aiche Journal,1991,37(9):1281-1292.
[25]RADHAKRISHNAN R, TROUT B L. A new approach for studying nucleation phenomena using molecular simulations:Application to CO2 hydrate clathrates [J]. Journal of Chemical Physics,2002, 117(4):1786-1796.
[26]GUO G J, LI M, ZHANG Y G, et al. Why can water cages adsorb aqueous methane? A potential of mean force calculation on hydrate nucleation mechanisms [J]. Physical Chemistry Chemical Physics,2009, 11(44):10427-10437.
[27]JACOBSON L C, HUJO W, MOLINERO V. Amorphous Precursors in the Nucleation of Clathrate Hydrates [J]. Journal of the American Chemical Society,2010,132(33):11806-11811.
[28]VATAMANU J, KUSALIK P G. Observation of two-step nucleation in methane hydrates [J]. Physical Chemistry Chemical Physics,2010,12(45):15065-15072.
[29]DING L Y, GENG C Y, ZHAO Y H, et al. Molecular dynamics simulation on the dissociation process of methane hydrates [J]. Molecular Simulation,2007,33(12):1005-1016.
[30]GENG C Y, HAN Q Z, WEN H, et al. Molecular dynamics simulation on the decomposition of type SII hydrogen hydrate and the performance of tetrahydrofuran as a stabiliser [J]. Molecular Simulation, 2010,36(6):474-483.
[31]MYSHAKIN E M, JIANG H, WARZINSKI R P, et al. Molecular Dynamics Simulations of Methane Hydrate Decomposition [J]. Journal of Physical Chemistry A,2009,113(10):1913-1921.
[32]SARUPRIA S, DEBENEDETTI P G. Molecular Dynamics Study of Carbon Dioxide Hydrate Dissociation [J]. Journal of Physical Chemistry A,2011,115(23):6102-6111.
[33]GENG C Y, WEN H, ZHOU H. Molecular Simulation of the Potential of Methane Reoccupation during the Replacement of Methane Hydrate by CO2 [J]. Journal of Physical Chemistry A,2009,113(18): 5463-5469.
[34]OTA M, MOROHASHI K, ABE Y, et al. Replacement of CH4 in the hydrate by use of liquid CO2 [J]. Energy Conversion and Management,2005,46(11-12):1680-1691.
[35]VORONOV V P, GORODETSKII E E, MURATOV A R. Experimental Study of Methane Replacement in Gas Hydrate by Carbon Dioxide [J]. Journal of Physical Chemistry B,2010,114(38): 12314-12318.
[36]OTA M, SAITO T, AIDA T, et al. Macro and microscopic CH4-CO2 replacement in CH4 hydrate under pressurized CO2 [J]. Aiche Journal,2007,53(10):2715-2721.
[37]QI Y X, OTA M, ZHANG H. Molecular dynamics simulation of replacement of CH4 in hydrate with CO2 [J]. Energy Conversion and Management,2011,52(7):2682-2687.
[38]BAI D, ZHANG X, WANG W. Replacement mechanism of methane hydrate with carbon dioxide from microsecond molecular dynamics simulations [J]. Energy& Environmental Science 2012,5: 7033-7041.
[39]DU Q S, LIU P J, DENG J. Empirical correction to molecular interaction energies in density functional theory (DFT) for methane hydrate simulation [J]. Journal of Chemical Theory and Computation, 2007,3(5):1665-1672.
[40]KUMAR P, SATHYAMURTHY N. Theoretical Studies of Host-Guest Interaction in Gas Hydrates [J]. Journal of Physical Chemistry A,2011,115:14276.
[41]SRIVASTAVA H K, SASTRY G N. Viability of Clathrate Hydrates as CO2 Capturing Agents:A Theoretical Study [J]. Journal of Physical Chemistry A,2011,115(26):7633-7637.
[42]LI Q, KOLB B, ROM N-P REZ G, et al. Ab initio energetics and kinetics study of H2 and CH4 in the SI clathrate hydrate [J]. Physical Review B,2011,84(15):153103.
[43]ALAVI S, RIPMEESTER J A. Hydrogen-gas migration through clathrate hydrate cages [J]. Angewandte Chemie-International Edition,2007,46(32):6102-6105.
[44]SIUDA P, SADLEJ J. Nuclear Magnetic Resonance Parameters for Methane Molecule Trapped in Clathrate Hydrates [J]. Journal of Physical Chemistry A,2011,115(5):612-619.
[45]UCHIDA T, OHMURA R, HORI A. Raman Peak Frequencies of Fluoromethane Molecules Measured in Clathrate Hydrate Crystals:Experimental Investigations and Density Functional Theory Calculations [J]. Journal of Physical Chemistry A,2010,114(1):317-323.
[46]HUO H, LIU Y, ZHENG Z Y, et al. Mechanical and thermal properties of methane clathrate hydrates as an alternative energy resource [J]. Journal of Renewable and Sustainable Energy,2011,3(6):063110.
[47]GUPTA, ASHIS, DIMMEL, et al. Carbon dioxide-hydrate product and method of manufacture thereof United States 6,858,240 [P/OL].2005.
[48]HATAKEYAMA T, AIDA E, YOKOMORI T, et al. Fire Extinction Using Carbon Dioxide Hydrate [J]. Industrial& Engineering Chemistry Research,2009,48(8):4083-4087.
[49]DAUBEROSGUTHORPE P, ROBERTS V A, OSGUTHORPE D J, et al. Structure and energetics of ligand-binding to proteins-escherichia-coli dihydrofolate reductase trimethoprim, a drug-receptor system [J]. Proteins-Structure Function and Genetics,1988,4(1):31-47.
[50]MARTIN R M. Electronic Structure Basic Theory and Practical Methods [M]. Cambridge: CAMBRIDGE UNIVERSITY PRESS,2004.
[51]张跃,谷景华,尚家香,马岳.计算材料学基础[M].北京：北京航空航天大学出版社,2007.
[52]林梦海.量子化学计算方法与应用[M].北京：科学出版社,2004.
[53]RILEY K E, PITONAK M, JURECKA P, et al. Stabilization and Structure Calculations for Noncovalent Interactions in Extended Molecular Systems Based on Wave Function and Density Functional Theories [J]. Chemical Reviews,2010,110(9):5023-5063.
[54]江建军,缪灵,梁培,et a1.计算材料学-—设计实践方法[M].北京：高等教育出版社,2010.
[55]DION M, RYDBERG H, SCHR, et al. Van der Waals Density Functional for General Geometries [J]. Physical Review Letters,2004,92(24):246401.
[56]GRIMME S. Density functional theory with London dispersion corrections [J]. Wiley Interdisciplinary Reviews:Computational Molecular Science,2011,1(2):211-228.
[57]GRIMME S. Semiempirical GGA-type density functional constructed with a long-range dispersion correction [J]. Journal of Computational Chemistry,2006,27(15):1787-1799.
[58]CHAI J D, HEAD-GORDON M. Long-range corrected hybrid density functionals with damped atom-atom dispersion corrections [J]. Physical Chemistry Chemical Physics,2008,10(44):6615-6620.
[59]VON LILIENFELD O A, TAVERNELLI I, ROTHLISBERGER U, et al. Optimization of Effective Atom Centered Potentials for London Dispersion Forces in Density Functional Theory [J]. Physical Review Letters,2004,93(15):153004.
[60]SUN Y Y, KIM Y H, LEE K, et al. Accurate and efficient calculation of van der Waals interactions within density functional theory by local atomic potential approach [J]. Journal of Chemical Physics,2008, 129(15):154102.
[61]ZHAO Y, TRUHLAR D G. A new local density functional for main-group thermochemistry, transition metal bonding, thermochemical kinetics, and noncovalent interactions [J]. Journal of Chemical Physics,2006,125(19):194101.
[62]ZHAO Y, TRUHLAR D G. Density functional for spectroscopy:No long-range self-interaction error, good performance for Rydberg and charge-transfer states, and better performance on average than B3LYP for ground states [J]. Journal of Physical Chemistry A,2006,110(49):13126-13130.
[63]ZHAO Y, TRUHLAR D G. The M06 suite of density functionals for main group thermochemistry, thermochemical kinetics, noncovalent interactions, excited states, and transition elements:two new functionals and systematic testing of four M06-class functionals and 12 other functionals [J]. Theoretical Chemistry Accounts,2008,120(1-3):215-241.
[64]CHAI J D, HEAD-GORDON M. Systematic optimization of long-range corrected hybrid density functionals [J]. Journal of Chemical Physics,2008,128:084106.
[65]VYDROV O A, SCUSERIA G E. Assessment of a long-range corrected hybrid functional [J]. Journal of Chemical Physics,2006,125:234109.
[66]STEPHENS P J, DEVLIN F J, CHABALOWSKI C F, et al. Ab initio calculation of vabrational absorption and circular-dichroism spectra using density functional force-fields [J]. Journal of Physical Chemistry,1994,98(45):11623-11627.
[67]BECKE A D. Density-functional thermochemistry the role of exact exchange [J]. Journal of Chemical Physics,1993,98(7):5648-5652.
[68]XU X, GODDARD W A. The X3LYP extended density functional for accurate descriptions of nonbond interactions, spin states, and thermochemical properties [J]. Proceedings of the National Academy of Sciences of the United States of America,2004,101(9):2673-2677.
[69]YANAI T, TEW D P, HANDY N C. A new hybrid exchange-correlation functional using the Coulomb-attenuating method (CAM-B3LYP) [J]. Chemical Physics Letters,2004,393(1-3):51-57.
[70]IIKURA H, TSUNEDA T, YANAI T, et al. A long-range correction scheme for generalized-gradient-approximation exchange functionals [J]. Journal of Chemical Physics,2001,115(8): 3540-3544.
[71]GRIMME S. Semiempirical hybrid density functional with perturbative second-order correlation [J]. Journal of Chemical Physics,2006,124:034108.
[72]SCHWABE T, GRIMME S. Towards chemical accuracy for the thermodynamics of large molecules: new hybrid density functionals including non-local correlation effects [J]. Physical Chemistry Chemical Physics,2006,8(38):4398-4401.
[73]LEE K, MURRAY E D, KONG L, et al. Higher-accuracy van der Waals density functional [J]. Physical Review B,2010,82(8):081101.
[74]VYDROV O A, VAN VOORHIS T. Nonlocal van der Waals Density Functional Made Simple [J]. Physical Review Letters,2009,103(6):063004.
[75]FRISCH M J, ET AL. Gaussian 09 [M]. Gaussian, Inc.,Wallingford CT.2009.
[76]Materials Studio [M]. San Diego; Accelrys Software Inc.2010.
[77]PERDEW J P, BURKE K, ERNZERHOF M. Generalized Gradient Approximation Made Simple [J]. Physical Review Letters,1996,77(18):3865.
[78]PERDEW J P, CHEVARY J A, VOSKO S H, et al. Atoms, molecules, solids, and surfaces: Applications of the generalized gradient approximation for exchange and correlation [J]. Physical Review B,1992,46(11):6671-6687.
[79]TAO J M, PERDEW J P, STAROVEROV V N, et al. Climbing the density functional ladder: Nonempirical meta-generalized gradient approximation designed for molecules and solids [J]. Physical Review Letters,2003,91:146401.
[80]TKATCHENKO A, SCHEFFLER M. Accurate Molecular Van Der Waals Interactions from Ground-State Electron Density and Free-Atom Reference Data [J]. Physical Review Letters,2009,102(7): 073005.
[81]ORTMANN F, BECHSTEDT F, SCHMIDT W G. Semiempirical van der Waals correction to the density functional description of solids and molecular structures [J]. Physical Review B,2006,73(20): 205101.
[82]BOYS S F, BERNARDI F. Calculation of small molecular interactions by differences of separate total energies-some procedures with reduced errors [J]. Molecular Physics,1970,19(4):553.
[83]XANTHEAS S S. On the importance of the fragment relaxation energy terms in the estimation of the basis set superposition error correction to the intermolecular interaction energy [J]. Journal of Chemical Physics,1996,104(21):8821-8824.
[84]CURTISS L A, FRURIP D J, BLANDER M. Studies of molecular association in H2O and D2O vapors by measurement of thermal-conductivity [J]. Journal of Chemical Physics,1979,71(6):2703-2711.
[85]REIMERS J R, WATTS R O, KLEIN M L. Intermolecular potential functions and the properties of water [J]. Chemical Physics,1982,64(1):95-114.
[86]ODUTOLA J A, DYKE T R. Partially deuterated water dimers microwave spectra and structure [J]. Journal of Chemical Physics,1980,72(9):5062-5070.
[87]DYKE T R, MACK K M, MUENTER J S. Structure of water dimer from molecular-beam electric resonance spectroscopy [J]. Journal of Chemical Physics,1977,66(2):498-510.
[88]BRYANTSEV V S, DIALLO M S, VAN DUIN A C T, et al. Evaluation of B3LYP, X3LYP, and M06-Class Density Functionals for Predicting the Binding Energies of Neutral, Protonated, and Deprotonated Water Clusters [J], Journal of Chemical Theory and Computation,2009,5(4):1016-1026.
[89]TSUZUKI S, HONDA K, UCHIMARU T, et al. Estimated MP2 and CCSD(T) interaction energies of n-alkane dimers at the basis set limit:Comparison of the methods of Helgaker et al. and Feller [J]. Journal of Chemical Physics,2006,124(11):114304.
[90]COPELAND K L, TSCHUMPER G S. Hydrocarbon/Water Interactions:Encouraging Energetics and Structures from DFT but Disconcerting Discrepancies for Hessian Indices [J]. J Chem Theory Comput, 2012,8:1646-1656.
[91]XANTHEAS S S, BURNHAM C J, HARRISON R J. Development of transferable interaction models for water. II. Accurate energetics of the first few water clusters from first principles [J]. Journal of Chemical Physics,2002,116(4):1493-1499.
[92]FEYEREISEN M W, FELLER D, DIXON D A. Hydrogen bond energy of the water dimer [J]. Journal of Physical Chemistry,1996,100(8):2993-2997.
[93]KIM K, JORDAN K D. Comparison of density-functional and MP2 calculations on the water monomer and dimer [J]. Journal of Physical Chemistry,1994,98(40):10089-10094.
[94]XANTHEAS S S, DUNNING T H. Ab initio studies of cylic water clusters (H2O)N, N= 1-6 optimal structures and vibrational spectra [J]. Journal of Chemical Physics,1993,99(11):8774-8792.
[95]LI A H T, CHAO S D. Intermolecular potentials of the methane dimer calculated with Moller-Plesset perturbation theory and density functional theory [J]. Journal of Chemical Physics,2006,125(9):094312.
[96]WEINHOLD F. Nature of H-bonding in clusters, liquids, and enzymes:an ab initio, natural bond orbital perspective [J]. Theochem-Journal of Molecular Structure,1997,398:181-197.
[97]WEINHOLD F. Quantum cluster equilibrium theory of liquids:Illustrative application to water [J]. Journal of Chemical Physics,1998,109(2):373-384.
[98]LUDWIG R, APPELHAGEN A. Calculation of clathrate-like water clusters including H2O-buckminsterfullerene [J]. Angewandte Chemie-International Edition,2005,44(5):811-815.
[99]FANOURGAKIS G S, APRA E, XANTHEAS S S. High-level ab initio calculations for the four low-lying families of minima of (H2O)(20). I. Estimates of MP2/CBS binding energies and comparison with empirical potentials [J]. Journal of Chemical Physics,2004,121(6):2655-2663.
[100]GOERIGK L, GRIMME S. A thorough benchmark of density functional methods for general main group thermochemistry, kinetics, and noncovalent interactions [J]. Physical Chemistry Chemical Physics, 2011,13(14):6670-6688.
[101]KHAN A. Theoretical studies of CH4(H20)2o, (H2O)21, (H2O)20, and fused dodecahedral and tetrakaidecahedral structures:How do natural gas hydrates form? [J]. Journal of Chemical Physics,1999, 110(24):11884-11889.
[102]GRIMME S, ANTONY J, SCHWABE T, et al. Density functional theory with dispersion corrections for supramolecular structures, aggregates, and complexes of (bio)organic molecules [J]. Organic& Biomolecular Chemistry,2007,5(5):741-758.
[103]BERNAL J D, FOWLER R H. A Theory of Water and Ionic Solution, with Particular Reference to Hydrogen and Hydroxyl Ions [J]. Journal of Chemical Physics,1933,1(8):515.
[104]OTA M, FERDOWS M. Monte Carlo approach to structure and thermodynamic property of CO2 hydrate [J]. Jsme International Journal Series B-Fluids and Thermal Engineering,2005,48(4):802-809.
[105]FERDOWS M, OTA M. Molecular simulation study for CO2 clathrate hydrate [J]. Chemical Engineering& Technology,2005,28(2):168-173.
[106]CHIALVO A A, HOUSSA M, CUMMINGS P T. Molecular dynamics study of the structure and thermophysical properties of model sI clathrate hydrates [J]. Journal of Physical Chemistry B,2002,106(2): 442-451.
[107]GREATHOUSE J A, CYGAN R T, SIMMONS B A. Vibrational spectra of methane clathrate hydrates from molecular dynamics simulation [J]. Journal of Physical Chemistry B,2006,110(13): 6428-6431.
[108]CARROLL J J, SLUPSKY J D, MATHER A E. The solubility of carbon dioxide in water at low-pressure [J]. Journal of Physical and Chemical Reference Data,1991,20(6):1201-1209.
[109]TENG H, YAMASAKI A, CHUN M K, et al. Solubility of liquid CO2 in water at temperatures from 278 K to 293 K and pressures from 6.44 MPa to 29.49 MPa and densities of the corresponding aqueous solutions [J]. Journal of Chemical Thermodynamics,1997,29(11):1301-1310.
[110]FAN S S, GUO T M. Hydrate formation of CO2-rich binary and quaternary gas mixtures in aqueous sodium chloride solutions [J]. Journal of Chemical and Engineering Data,1999,44(4):829-832.
[111]OHGAKI K, HAMANAKA T. Phase behavior of CO2 hydrate-liquid CO2-H2O system at high-pressure [J]. Kagaku Kogaku Ronbunshu,1995,21(4):800-803.
[112]ALADKO E Y, DYADIN Y A, FENELONOV V B, et al. Formation and decomposition of ethane, propane, and carbon dioxide hydrates in silica gel mesopores under high pressure [J]. Journal of Physical Chemistry B,2006,110(39):19717-19725.
[113]NAKANO S, MORITOKI M, OHGAKI K. High-pressure phase equilibrium and Raman microprobe spectroscopic studies on the CO2 hydrate system [J]. Journal of Chemical and Engineering Data,1998, 43(5):807-810.
[114]ALLEN M P, TILDESLEY D J. Computer Simulation of Liquids [M]. Oxford University Press, 1987.
[115]IWAI Y, NAKAMURA H, ARAI Y, et al. Analysis of dissociation process for gas hydrates by molecular dynamics simulation [J]. Molecular Simulation,2010,36(3):246-253.
[116]OKUCHI T, TAKIGAWA M, SHU J F, et al. Fast molecular transport in hydrogen hydrates by high-pressure diamond anvil cell NMR [J]. Physical Review B,2007,75:144104.
[2]陈光进,孙长宇,马庆兰.气体水合物科学与技术[M].北京：化学工业出版社,2007.
[3]周怀阳,彭小彤,叶瑛.天然气水合物[M].北京：海洋出版社,2000.
[4]SLOAN E D. Fundamental principles and applications of natural gas hydrates [J]. Nature,2003, 426(6964):353-359.
[5]SUM A K, KOH C A, SLOAN E D. Clathrate Hydrates:From Laboratory Science to Engineering Practice [J]. Industrial& Engineering Chemistry Research,2009,48(16):7457-7465.
[6]KOH C A, SUM A K, SLOAN E D. Gas hydrates:Unlocking the energy from icy cages [J]. Journal of Applied Physics,2009,106(6):061101.
[7]VOS W L, FINGER L W, HEMLEY R J, et al. Novel H2-H2O clathrates at high pressures [J]. Physical Review Letters,1993,71(19):3150-3153.
[8]FLORUSSE L J, PETERS C J, SCHOONMAN J, et al. Stable low-pressure hydrogen clusters stored in a binary clathrate hydrate [J]. Science,2004,306(5695):469-471.
[9]UDACHIN K A, RATCLIFFE C I, RIPMEESTER J A. Structure, composition, and thermal expansion of CO2 hydrate from single crystal X-ray diffraction measurements [J]. Journal of Physical Chemistry B,2001,105(19):4200-4204.
[10]UCHIDA T, TAKEYA S, KAMATA Y, et al. Spectroscopic observations and thermodynamic calculations on clathrate hydrates of mixed gas containing methane and ethane:Determination of structure, composition and cage occupancy [J]. Journal of Physical Chemistry B,2002,106(48):12426-12431.
[11]UCHIDA T, TAKAGI A, KAWABATA J, et al. Raman spectroscopic analyses on the growth process of CO2 hydrates [J]. Energy Conversion and Management,1995,36(6-9):547-550.
[12]SUSILO R, RIPMEESTER J A, ENGLEZOS P. Characterization of gas hydrates with PXRD, DSC, NMR, and Raman spectroscopy [J]. Chemical Engineering Science,2007,62(15):3930-3939.
[13]SUM A K, BURRUSS R C, SLOAN E D. Measurement of clathrate hydrates via Raman spectroscopy [J]. Journal of Physical Chemistry B,1997,101(38):7371-7377.
[14]SUBRAMANIAN S, SLOAN E D. Trends in vibrational frequencies of guests trapped in clathrate hydrate cages [J]. Journal of Physical Chemistry B,2002,106(17):4348-4355.
[15]SUBRAMANIAN S, KINI R A, DEC S F, et al. Evidence of structure II hydrate formation from methane plus ethane mixtures [J]. Chemical Engineering Science,2000,55(11):1981-1999.
[16]RAWN C J, RONDINONE A J, CHAKOUMAKOS B C, et al. Neutron powder diffraction studies as a function of temperature of structure II hydrate formed from propane [J]. Canadian Journal of Physics, 2003,81(1-2):431-438.
[17]KUMAR R, LANG S, ENGLEZOS P, et al. Application of the ATR-IR Spectroscopic Technique to the Characterization of Hydrates Formed by CO2, CO2/H2 and CO2/H2/C3H8 [J]. Journal of Physical Chemistry A,2009,113(22):6308-6313.
[18]GUTT C, ASMUSSEN B, PRESS W, et al. The structure of deuterated methane-hydrate [J]. Journal of Chemical Physics,2000,113(11):4713-4721.
[19]UDACHIN K A, I. R C, A. R J. Single Crystal Diffraction Studies of Structure I, II and H Hydrates: Structure, Cage Occupancy and Composition [J]. Journal of Supramolecular Chemistry,2002,2:405-408.
[20]KIRCHNER M T, BOESE R, BILLUPS W E, et al. Gas hydrate single-crystal structure analyses [J]. Journal of the American Chemical Society,2004,126(30):9407-9412.
[21]GUPTA A, DEC S F, KOH C A, et al. NMR investigation of methane hydrate dissociation [J]. Journal of Physical Chemistry C,2007,111(5):2341-2346.
[22]CHOU I M, SHARMA A, BURRUSS R C, et al. Transformations in methane hydrates [J]. Proceedings of the National Academy of Sciences of the United States of America,2000,97(25): 13484-13487.
[23]CHRISTIANSEN R L, SLOAN E D. Mechanisms and Kinetics of Hydrate Formation [M]//SLOAN E D, HAPPEL J, HNATOW M A. International Conference on Natural Gas Hydrates.1994:283-305.
[24]SLOAN E D, FLEYFEL F. A molecular mechanism for gas hydrate nucleation from ice [J]. Aiche Journal,1991,37(9):1281-1292.
[25]RADHAKRISHNAN R, TROUT B L. A new approach for studying nucleation phenomena using molecular simulations:Application to CO2 hydrate clathrates [J]. Journal of Chemical Physics,2002, 117(4):1786-1796.
[26]GUO G J, LI M, ZHANG Y G, et al. Why can water cages adsorb aqueous methane? A potential of mean force calculation on hydrate nucleation mechanisms [J]. Physical Chemistry Chemical Physics,2009, 11(44):10427-10437.
[27]JACOBSON L C, HUJO W, MOLINERO V. Amorphous Precursors in the Nucleation of Clathrate Hydrates [J]. Journal of the American Chemical Society,2010,132(33):11806-11811.
[28]VATAMANU J, KUSALIK P G. Observation of two-step nucleation in methane hydrates [J]. Physical Chemistry Chemical Physics,2010,12(45):15065-15072.
[29]DING L Y, GENG C Y, ZHAO Y H, et al. Molecular dynamics simulation on the dissociation process of methane hydrates [J]. Molecular Simulation,2007,33(12):1005-1016.
[30]GENG C Y, HAN Q Z, WEN H, et al. Molecular dynamics simulation on the decomposition of type SII hydrogen hydrate and the performance of tetrahydrofuran as a stabiliser [J]. Molecular Simulation, 2010,36(6):474-483.
[31]MYSHAKIN E M, JIANG H, WARZINSKI R P, et al. Molecular Dynamics Simulations of Methane Hydrate Decomposition [J]. Journal of Physical Chemistry A,2009,113(10):1913-1921.
[32]SARUPRIA S, DEBENEDETTI P G. Molecular Dynamics Study of Carbon Dioxide Hydrate Dissociation [J]. Journal of Physical Chemistry A,2011,115(23):6102-6111.
[33]GENG C Y, WEN H, ZHOU H. Molecular Simulation of the Potential of Methane Reoccupation during the Replacement of Methane Hydrate by CO2 [J]. Journal of Physical Chemistry A,2009,113(18): 5463-5469.
[34]OTA M, MOROHASHI K, ABE Y, et al. Replacement of CH4 in the hydrate by use of liquid CO2 [J]. Energy Conversion and Management,2005,46(11-12):1680-1691.
[35]VORONOV V P, GORODETSKII E E, MURATOV A R. Experimental Study of Methane Replacement in Gas Hydrate by Carbon Dioxide [J]. Journal of Physical Chemistry B,2010,114(38): 12314-12318.
[36]OTA M, SAITO T, AIDA T, et al. Macro and microscopic CH4-CO2 replacement in CH4 hydrate under pressurized CO2 [J]. Aiche Journal,2007,53(10):2715-2721.
[37]QI Y X, OTA M, ZHANG H. Molecular dynamics simulation of replacement of CH4 in hydrate with CO2 [J]. Energy Conversion and Management,2011,52(7):2682-2687.
[38]BAI D, ZHANG X, WANG W. Replacement mechanism of methane hydrate with carbon dioxide from microsecond molecular dynamics simulations [J]. Energy& Environmental Science 2012,5: 7033-7041.
[39]DU Q S, LIU P J, DENG J. Empirical correction to molecular interaction energies in density functional theory (DFT) for methane hydrate simulation [J]. Journal of Chemical Theory and Computation, 2007,3(5):1665-1672.
[40]KUMAR P, SATHYAMURTHY N. Theoretical Studies of Host-Guest Interaction in Gas Hydrates [J]. Journal of Physical Chemistry A,2011,115:14276.
[41]SRIVASTAVA H K, SASTRY G N. Viability of Clathrate Hydrates as CO2 Capturing Agents:A Theoretical Study [J]. Journal of Physical Chemistry A,2011,115(26):7633-7637.
[42]LI Q, KOLB B, ROM N-P REZ G, et al. Ab initio energetics and kinetics study of H2 and CH4 in the SI clathrate hydrate [J]. Physical Review B,2011,84(15):153103.
[43]ALAVI S, RIPMEESTER J A. Hydrogen-gas migration through clathrate hydrate cages [J]. Angewandte Chemie-International Edition,2007,46(32):6102-6105.
[44]SIUDA P, SADLEJ J. Nuclear Magnetic Resonance Parameters for Methane Molecule Trapped in Clathrate Hydrates [J]. Journal of Physical Chemistry A,2011,115(5):612-619.
[45]UCHIDA T, OHMURA R, HORI A. Raman Peak Frequencies of Fluoromethane Molecules Measured in Clathrate Hydrate Crystals:Experimental Investigations and Density Functional Theory Calculations [J]. Journal of Physical Chemistry A,2010,114(1):317-323.
[46]HUO H, LIU Y, ZHENG Z Y, et al. Mechanical and thermal properties of methane clathrate hydrates as an alternative energy resource [J]. Journal of Renewable and Sustainable Energy,2011,3(6):063110.
[47]GUPTA, ASHIS, DIMMEL, et al. Carbon dioxide-hydrate product and method of manufacture thereof United States 6,858,240 [P/OL].2005.
[48]HATAKEYAMA T, AIDA E, YOKOMORI T, et al. Fire Extinction Using Carbon Dioxide Hydrate [J]. Industrial& Engineering Chemistry Research,2009,48(8):4083-4087.
[49]DAUBEROSGUTHORPE P, ROBERTS V A, OSGUTHORPE D J, et al. Structure and energetics of ligand-binding to proteins-escherichia-coli dihydrofolate reductase trimethoprim, a drug-receptor system [J]. Proteins-Structure Function and Genetics,1988,4(1):31-47.
[50]MARTIN R M. Electronic Structure Basic Theory and Practical Methods [M]. Cambridge: CAMBRIDGE UNIVERSITY PRESS,2004.
[51]张跃,谷景华,尚家香,马岳.计算材料学基础[M].北京：北京航空航天大学出版社,2007.
[52]林梦海.量子化学计算方法与应用[M].北京：科学出版社,2004.
[53]RILEY K E, PITONAK M, JURECKA P, et al. Stabilization and Structure Calculations for Noncovalent Interactions in Extended Molecular Systems Based on Wave Function and Density Functional Theories [J]. Chemical Reviews,2010,110(9):5023-5063.
[54]江建军,缪灵,梁培,et a1.计算材料学-—设计实践方法[M].北京：高等教育出版社,2010.
[55]DION M, RYDBERG H, SCHR, et al. Van der Waals Density Functional for General Geometries [J]. Physical Review Letters,2004,92(24):246401.
[56]GRIMME S. Density functional theory with London dispersion corrections [J]. Wiley Interdisciplinary Reviews:Computational Molecular Science,2011,1(2):211-228.
[57]GRIMME S. Semiempirical GGA-type density functional constructed with a long-range dispersion correction [J]. Journal of Computational Chemistry,2006,27(15):1787-1799.
[58]CHAI J D, HEAD-GORDON M. Long-range corrected hybrid density functionals with damped atom-atom dispersion corrections [J]. Physical Chemistry Chemical Physics,2008,10(44):6615-6620.
[59]VON LILIENFELD O A, TAVERNELLI I, ROTHLISBERGER U, et al. Optimization of Effective Atom Centered Potentials for London Dispersion Forces in Density Functional Theory [J]. Physical Review Letters,2004,93(15):153004.
[60]SUN Y Y, KIM Y H, LEE K, et al. Accurate and efficient calculation of van der Waals interactions within density functional theory by local atomic potential approach [J]. Journal of Chemical Physics,2008, 129(15):154102.
[61]ZHAO Y, TRUHLAR D G. A new local density functional for main-group thermochemistry, transition metal bonding, thermochemical kinetics, and noncovalent interactions [J]. Journal of Chemical Physics,2006,125(19):194101.
[62]ZHAO Y, TRUHLAR D G. Density functional for spectroscopy:No long-range self-interaction error, good performance for Rydberg and charge-transfer states, and better performance on average than B3LYP for ground states [J]. Journal of Physical Chemistry A,2006,110(49):13126-13130.
[63]ZHAO Y, TRUHLAR D G. The M06 suite of density functionals for main group thermochemistry, thermochemical kinetics, noncovalent interactions, excited states, and transition elements:two new functionals and systematic testing of four M06-class functionals and 12 other functionals [J]. Theoretical Chemistry Accounts,2008,120(1-3):215-241.
[64]CHAI J D, HEAD-GORDON M. Systematic optimization of long-range corrected hybrid density functionals [J]. Journal of Chemical Physics,2008,128:084106.
[65]VYDROV O A, SCUSERIA G E. Assessment of a long-range corrected hybrid functional [J]. Journal of Chemical Physics,2006,125:234109.
[66]STEPHENS P J, DEVLIN F J, CHABALOWSKI C F, et al. Ab initio calculation of vabrational absorption and circular-dichroism spectra using density functional force-fields [J]. Journal of Physical Chemistry,1994,98(45):11623-11627.
[67]BECKE A D. Density-functional thermochemistry the role of exact exchange [J]. Journal of Chemical Physics,1993,98(7):5648-5652.
[68]XU X, GODDARD W A. The X3LYP extended density functional for accurate descriptions of nonbond interactions, spin states, and thermochemical properties [J]. Proceedings of the National Academy of Sciences of the United States of America,2004,101(9):2673-2677.
[69]YANAI T, TEW D P, HANDY N C. A new hybrid exchange-correlation functional using the Coulomb-attenuating method (CAM-B3LYP) [J]. Chemical Physics Letters,2004,393(1-3):51-57.
[70]IIKURA H, TSUNEDA T, YANAI T, et al. A long-range correction scheme for generalized-gradient-approximation exchange functionals [J]. Journal of Chemical Physics,2001,115(8): 3540-3544.
[71]GRIMME S. Semiempirical hybrid density functional with perturbative second-order correlation [J]. Journal of Chemical Physics,2006,124:034108.
[72]SCHWABE T, GRIMME S. Towards chemical accuracy for the thermodynamics of large molecules: new hybrid density functionals including non-local correlation effects [J]. Physical Chemistry Chemical Physics,2006,8(38):4398-4401.
[73]LEE K, MURRAY E D, KONG L, et al. Higher-accuracy van der Waals density functional [J]. Physical Review B,2010,82(8):081101.
[74]VYDROV O A, VAN VOORHIS T. Nonlocal van der Waals Density Functional Made Simple [J]. Physical Review Letters,2009,103(6):063004.
[75]FRISCH M J, ET AL. Gaussian 09 [M]. Gaussian, Inc.,Wallingford CT.2009.
[76]Materials Studio [M]. San Diego; Accelrys Software Inc.2010.
[77]PERDEW J P, BURKE K, ERNZERHOF M. Generalized Gradient Approximation Made Simple [J]. Physical Review Letters,1996,77(18):3865.
[78]PERDEW J P, CHEVARY J A, VOSKO S H, et al. Atoms, molecules, solids, and surfaces: Applications of the generalized gradient approximation for exchange and correlation [J]. Physical Review B,1992,46(11):6671-6687.
[79]TAO J M, PERDEW J P, STAROVEROV V N, et al. Climbing the density functional ladder: Nonempirical meta-generalized gradient approximation designed for molecules and solids [J]. Physical Review Letters,2003,91:146401.
[80]TKATCHENKO A, SCHEFFLER M. Accurate Molecular Van Der Waals Interactions from Ground-State Electron Density and Free-Atom Reference Data [J]. Physical Review Letters,2009,102(7): 073005.
[81]ORTMANN F, BECHSTEDT F, SCHMIDT W G. Semiempirical van der Waals correction to the density functional description of solids and molecular structures [J]. Physical Review B,2006,73(20): 205101.
[82]BOYS S F, BERNARDI F. Calculation of small molecular interactions by differences of separate total energies-some procedures with reduced errors [J]. Molecular Physics,1970,19(4):553.
[83]XANTHEAS S S. On the importance of the fragment relaxation energy terms in the estimation of the basis set superposition error correction to the intermolecular interaction energy [J]. Journal of Chemical Physics,1996,104(21):8821-8824.
[84]CURTISS L A, FRURIP D J, BLANDER M. Studies of molecular association in H2O and D2O vapors by measurement of thermal-conductivity [J]. Journal of Chemical Physics,1979,71(6):2703-2711.
[85]REIMERS J R, WATTS R O, KLEIN M L. Intermolecular potential functions and the properties of water [J]. Chemical Physics,1982,64(1):95-114.
[86]ODUTOLA J A, DYKE T R. Partially deuterated water dimers microwave spectra and structure [J]. Journal of Chemical Physics,1980,72(9):5062-5070.
[87]DYKE T R, MACK K M, MUENTER J S. Structure of water dimer from molecular-beam electric resonance spectroscopy [J]. Journal of Chemical Physics,1977,66(2):498-510.
[88]BRYANTSEV V S, DIALLO M S, VAN DUIN A C T, et al. Evaluation of B3LYP, X3LYP, and M06-Class Density Functionals for Predicting the Binding Energies of Neutral, Protonated, and Deprotonated Water Clusters [J], Journal of Chemical Theory and Computation,2009,5(4):1016-1026.
[89]TSUZUKI S, HONDA K, UCHIMARU T, et al. Estimated MP2 and CCSD(T) interaction energies of n-alkane dimers at the basis set limit:Comparison of the methods of Helgaker et al. and Feller [J]. Journal of Chemical Physics,2006,124(11):114304.
[90]COPELAND K L, TSCHUMPER G S. Hydrocarbon/Water Interactions:Encouraging Energetics and Structures from DFT but Disconcerting Discrepancies for Hessian Indices [J]. J Chem Theory Comput, 2012,8:1646-1656.
[91]XANTHEAS S S, BURNHAM C J, HARRISON R J. Development of transferable interaction models for water. II. Accurate energetics of the first few water clusters from first principles [J]. Journal of Chemical Physics,2002,116(4):1493-1499.
[92]FEYEREISEN M W, FELLER D, DIXON D A. Hydrogen bond energy of the water dimer [J]. Journal of Physical Chemistry,1996,100(8):2993-2997.
[93]KIM K, JORDAN K D. Comparison of density-functional and MP2 calculations on the water monomer and dimer [J]. Journal of Physical Chemistry,1994,98(40):10089-10094.
[94]XANTHEAS S S, DUNNING T H. Ab initio studies of cylic water clusters (H2O)N, N= 1-6 optimal structures and vibrational spectra [J]. Journal of Chemical Physics,1993,99(11):8774-8792.
[95]LI A H T, CHAO S D. Intermolecular potentials of the methane dimer calculated with Moller-Plesset perturbation theory and density functional theory [J]. Journal of Chemical Physics,2006,125(9):094312.
[96]WEINHOLD F. Nature of H-bonding in clusters, liquids, and enzymes:an ab initio, natural bond orbital perspective [J]. Theochem-Journal of Molecular Structure,1997,398:181-197.
[97]WEINHOLD F. Quantum cluster equilibrium theory of liquids:Illustrative application to water [J]. Journal of Chemical Physics,1998,109(2):373-384.
[98]LUDWIG R, APPELHAGEN A. Calculation of clathrate-like water clusters including H2O-buckminsterfullerene [J]. Angewandte Chemie-International Edition,2005,44(5):811-815.
[99]FANOURGAKIS G S, APRA E, XANTHEAS S S. High-level ab initio calculations for the four low-lying families of minima of (H2O)(20). I. Estimates of MP2/CBS binding energies and comparison with empirical potentials [J]. Journal of Chemical Physics,2004,121(6):2655-2663.
[100]GOERIGK L, GRIMME S. A thorough benchmark of density functional methods for general main group thermochemistry, kinetics, and noncovalent interactions [J]. Physical Chemistry Chemical Physics, 2011,13(14):6670-6688.
[101]KHAN A. Theoretical studies of CH4(H20)2o, (H2O)21, (H2O)20, and fused dodecahedral and tetrakaidecahedral structures:How do natural gas hydrates form? [J]. Journal of Chemical Physics,1999, 110(24):11884-11889.
[102]GRIMME S, ANTONY J, SCHWABE T, et al. Density functional theory with dispersion corrections for supramolecular structures, aggregates, and complexes of (bio)organic molecules [J]. Organic& Biomolecular Chemistry,2007,5(5):741-758.
[103]BERNAL J D, FOWLER R H. A Theory of Water and Ionic Solution, with Particular Reference to Hydrogen and Hydroxyl Ions [J]. Journal of Chemical Physics,1933,1(8):515.
[104]OTA M, FERDOWS M. Monte Carlo approach to structure and thermodynamic property of CO2 hydrate [J]. Jsme International Journal Series B-Fluids and Thermal Engineering,2005,48(4):802-809.
[105]FERDOWS M, OTA M. Molecular simulation study for CO2 clathrate hydrate [J]. Chemical Engineering& Technology,2005,28(2):168-173.
[106]CHIALVO A A, HOUSSA M, CUMMINGS P T. Molecular dynamics study of the structure and thermophysical properties of model sI clathrate hydrates [J]. Journal of Physical Chemistry B,2002,106(2): 442-451.
[107]GREATHOUSE J A, CYGAN R T, SIMMONS B A. Vibrational spectra of methane clathrate hydrates from molecular dynamics simulation [J]. Journal of Physical Chemistry B,2006,110(13): 6428-6431.
[108]CARROLL J J, SLUPSKY J D, MATHER A E. The solubility of carbon dioxide in water at low-pressure [J]. Journal of Physical and Chemical Reference Data,1991,20(6):1201-1209.
[109]TENG H, YAMASAKI A, CHUN M K, et al. Solubility of liquid CO2 in water at temperatures from 278 K to 293 K and pressures from 6.44 MPa to 29.49 MPa and densities of the corresponding aqueous solutions [J]. Journal of Chemical Thermodynamics,1997,29(11):1301-1310.
[110]FAN S S, GUO T M. Hydrate formation of CO2-rich binary and quaternary gas mixtures in aqueous sodium chloride solutions [J]. Journal of Chemical and Engineering Data,1999,44(4):829-832.
[111]OHGAKI K, HAMANAKA T. Phase behavior of CO2 hydrate-liquid CO2-H2O system at high-pressure [J]. Kagaku Kogaku Ronbunshu,1995,21(4):800-803.
[112]ALADKO E Y, DYADIN Y A, FENELONOV V B, et al. Formation and decomposition of ethane, propane, and carbon dioxide hydrates in silica gel mesopores under high pressure [J]. Journal of Physical Chemistry B,2006,110(39):19717-19725.
[113]NAKANO S, MORITOKI M, OHGAKI K. High-pressure phase equilibrium and Raman microprobe spectroscopic studies on the CO2 hydrate system [J]. Journal of Chemical and Engineering Data,1998, 43(5):807-810.
[114]ALLEN M P, TILDESLEY D J. Computer Simulation of Liquids [M]. Oxford University Press, 1987.
[115]IWAI Y, NAKAMURA H, ARAI Y, et al. Analysis of dissociation process for gas hydrates by molecular dynamics simulation [J]. Molecular Simulation,2010,36(3):246-253.
[116]OKUCHI T, TAKIGAWA M, SHU J F, et al. Fast molecular transport in hydrogen hydrates by high-pressure diamond anvil cell NMR [J]. Physical Review B,2007,75:144104.