Calculation of second virial coefficients using ab initio intermolecular pair potentials for F2-F2 and H2-F2 dimers

Ab Initio Intermolecular Potential Energy Surfaces and Cross Second Virial Coefficients for the Dimer N2-NO

“…It is our experience, however, that the extrapolation scheme is adequate. ,, The use of extrapolation equation eq is acceptable to the calculation of ab initio energy. Moreover, the extrapolation results proven are well consistent with experimental values, as demonstrated in the published articles. ,,− In all cases, the extrapolation to the complete basis set (CBS) limit has a significant effect on the calculated energy values. From the considered results, we can utilize the basis sets aug-cc-pV m Z ( m = 4, 24) for all calculations.…”

“…Furthermore, the difference between ARE,% values of two basis sets aug-cc-pV m Z (with m = 4, 24) is insignificant. In general, the bond lengths of nitrogen and nitric oxide obtained from the basis sets aug-cc-pV m Z ( m = 23, 24, 34), which are extrapolated according to the appropriate equation eq , − ,, are very close to the experimental values (Exp.). Thus, this proves that the basis sets aug-cc-pV m Z (with m = 4, 24) are most suitable for intermolecular energy calculation of the system N 2 and NO.…”

“…In several published studies, it has been shown that the 5-site pair models give a reasonable representation. ,,− It is very important for us to carefully build the structure of a new 5-site potential function. We have developed the ab initio 5-site Morse-style potentials for mixtures H 2 -O 2 , N 2 -H 2 , and F 2 -H 2 . − In this work the Morse-style 5-site interaction potentials have been modified newly to obtain the global fit of ab initio energy values for the N 2 -NO. We constructed successfully the new two-body potential function.…”

“…We have found the ab initio potential functions that are predominantly different from the Morse-type functions published in the interaction terms and damping functions f 1 ( r ij ) and f n ( r ij ). These two potential functions built here have been greatly modified compared to the ab initio potentials in the published works. − The new 5-site potentials obtained here are fully adaptable to the ab initio global potential surface that is specific to the dimer N 2 -NO. According to our experience and previously published articles, ,− the adjustable parameters De, α, β, and C n are optimized appropriately to utilize for the short-range and long-range interactions.…”

Validation of thermophysical data for scientific and engineering applications

“…The accuracy of the property predictions may be as good or better than experimental measurements for some properties, such as virial coefficients and heat capacities of simple diluted gases, cf. [50,51], and gasphase enthalpies of formation, cf. [52].…”