Second Virial Coefficients for N 2 ···H 2 and NH···NH

High Resolution Image Download MS PowerPoint Slide Thermodynamic properties of real gases can be accurately described using realistic intermolecular potential energy surfaces. In this work, a first-order correction to the ideal gas equation of state is introduced through the computation of the classical second virial coefficient, B ( T ), derived from the configurational partition function, which explicitly depends on the intermolecular interaction potential. As a case study, the double many-body expansion (DMBE) potential energy surface for the ground electronic state of the N 2 H 2 system was employed to derive pairwise interaction potentials for H 2 ···N 2 and NH···NH. These potentials were used to numerically evaluate the canonical partition function. Second virial coefficients, compressibility factors, and constant-volume heat capacities were computed in the temperature range 30–2000 K. The calculated B ( T ) values for H 2 ···N 2 are in good agreement with previous literature data, while the results for NH···NH lie within expected trends observed for similar systems.