A New Database and Benchmark of the Bond Energies of Noble-Gas Containing Molecules

Abstract

We have developed a new database of structures and bond energies of 45 noble-gas containing molecules. The structures were calculated by CCSD(T)/aug-cc-pVTZ methods and the bond energies were obtained using CCSD(T)/CBS (complete basis set) method. Many wavefunction-based and density functional theory methods have been benchmarked against the 45 accurate bond energies. Our result showed that the MPW1B95, B2GP-PLYP, and DSD-BLYP functionals with the aug-cc-pVTZ basis set excel on predicting the bond energies of the noble-gas molecules with MUEs (mean unsigned errors) of 1.5-1.9 kcal/mol. When combinations of Dunning's basis sets are used, the MPW1B95, MPW1PW91, and B2GP-PLYP functional give significantly lower MUEs of 1.1-1.3 kcal/mol. Doubly hybrid methods using B2GP-PLYP and DSD-BLYP functionals and MP2 calculation also provide satisfactory accuracy with MUEs of 1.3-1.4 kcal/mol. If the noble-gas bond energies and the total atomization energies of a group of 109 main-group molecules are considered at the same time, the MPW1B95/aug-cc-pVTZ single-level method (MUE = 2.7 kcal/mol) and the B2GP-PLYP functional with combinations of basis sets (MUEs = 1.8 kcal/mol) give the overall best result.

Theoretical Prediction on the New Types of Noble Gas Containing Anions OBONgO− and OCNNgO− (Ng=He, Ar, Kr and Xe)

“…The zero-point energies make a significant correction for Ng=He on the three-body dissociation channel. The values obtained at the MP2/aptz level overestimate the stability by 13–21 kcal/mol, which is consistent with earlier studies [ 20 , 22 , 36 , 42 ]. The barrier heights of the two-body dissociation at the CCSD(T)/apqz level are 6–32 kcal/mol.…”

“…They were also obtained using the B3LYP [ 34 ] and MPW1B95 [ 35 ] hybrid density functional theory with the aug-cc-pVTZ basis set. A recent benchmark study [ 36 ] has shown that the MPW1B95 functional gave a very accurate prediction of the noble gas bonding energies. Single-point energy calculation was also performed using the CCSD(T) theory [ 37 ] with the aug-cc-pVTZ and aug-cc-pVQZ basis sets to acquire more accurate relative energies.…”

Noble Gas in a Ring

“…For Xe, the aug-cc-pVTZ-pp basis set was used where the 28 core electrons were represented by a relativistic effective potential [ 30 ] which takes the scalar relativistic effects into account. Diffuse functions were included because recent research shows they are crucial for obtaining accurate bond energies for noble-gas containing molecules [ 31 ]. The basis set is abbreviated as aptz in the rest of this article.…”