Reliable results for the Isotropic Dipole – Dipole and Triple – Dipole Dispersion Energy Coefficients for Interactions involving Formaldehyde,Acetaldehyde,Acetone,and Mono -,Di -,and Tri - Methylamine

Abstract

Pseudo – spectral dipole oscillator strengths and excitation energies, which are discrete representations of previously developed recommended continuous dipole oscillator strength distributions(DOSDs), are presented for the ground state formaldehyde, acetaldehyde, acetone, and mono - , di - , and tri – methylamine molecules. These pseudo – DOSDs, together with previously published pseudo – DOSDs for other atoms and molecules, are used to evaluate the dipole – dipole and the triple – dipole dispersion energy coefficients for all the two – body and three - body interactions between H₂CO, CH₃CHO, (CH₃)₂CO, CH₃NH₂, (CH₃)₂ NH, and (CH₃)₃N, and between these molecules and forty – four other species, namely Cl₂, SiH₄, SiF₄, CCl₄, H, Li, He, Ne, Ar, Kr, Xe, SF6, HF, HCl, HBr, SO₂, CS₂, OCS, H₂, N₂, O₂, NO, N₂O, H₂O, H₂S, NH₃, CO, CO₂, the normal alkanes CH₄, C₂H₆, C₃H₈, C₄H₁₀, C₅H₁₂, C₆H₁₄, C₇H₁₆ and C₈H₁₈, the 1-alkenes C₂H₄, C₃H₆ and C₄H₈, C₂H₂, C₆H₆, and the primary alcohols CH₃OH, C₂H₅OH and C₃H₇OH. Results are presented explicitly for all the dipole – dipole dispersion energy coefficients and for the triple – dipole coefficients for all three -body interactions involving the H₂CO, CH₃CHO, (CH₃)₂CO, CH₃NH₂, (CH₃)₂ NH, and (CH₃)₃N molecules. The estimated errors in the two - body and three – coefficients are 1% and 1–2%