The solid phase model of Paricaud' is used, in conjunction with the predictive Soave-Redlich-Kwong (PSRK) equation of state,(2) to correlate the thermodynamic equilibrium conditions of TBAB and TBAC semiclathrates formed in the presence of pure gases. Unlike many previous modeling efforts, the current approach does not neglect the solubility of the gas in the aqueous phase or the presence of water in the vapor phase. Rather, the solubility of the gas and molar fraction of water in vapor phase are computed from a flash calculation. Furthermore, the new approach also computes the Langmuir constants from the Kihara potential rather than from the square well potential or from an empirical correlation. The new modeling approach is applied to TBAB and TBAC semiclathrates that are formed in the presence of Xe, Ar, CH4, CO2, N-2, and H-2. For all of the gases, new Kihara potential parameters were regressed from the experimental data. It was found that the new approach was able to correlate the experimental data to a high degree of accuracy with fewer adjustable parameters than all but one of the existing modeling attempts.