The van der Waals interactions in rare-gas dimers: the role of interparticle interactions

Abstract

We investigate the potential energy curves of rare-gas dimers with various ranges and strengths of interparticle interactions (nuclear-electron, electron-electron, and nuclear-nuclear interactions).Our investigation is based on the highly accurate coupled-cluster theory associated with those interparticle interactions. For comparison, the performance of the corresponding Hartree-Fock theory, second-order Møller-Plesset perturbation theory, and density functional theory is also investigated.Our results reveal that when the interparticle interactions retain the long-range Coulomb tails, the nature of van der Waals interactions in the rare-gas dimers remains similar. By contrast, when the interparticle interactions are sufficiently short-range, the conventional van der Waals interactions in the rare-gas dimers completely disappear, yielding purely repulsive potential energy curves.

SCAN-based hybrid and double-hybrid density functionals from models without fitted parameters

“…For the noncovalent interactions of the S22 and S66 sets, the SCAN-based semilocal, hybrid, and double-hybrid functionals consistently outperform their PBE-based counterparts, which may be attributed to the improved performance of SCAN for noncovalent interactions (mainly due to its improved treatment of medium-range dynamical correlation effects), with respect to PBE. Nonetheless, as SCAN and PBE are both semilocal functionals, they cannot adequately describe the van der Waals (vdW) asymptote [10,15], which requires an accurate treatment of long-range dynamical correlation effects. Incorporating SCAN and PBE with the double-hybrid schemes [38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55], the DFT-D (KS-DFT with empirical dispersion corrections) schemes [44,[82][83][84][85][86][87][88], or fully nonlocal density functionals [89][90][91] may greatly improve the accuracy of SCAN and PBE for vdW interactions.…”

“…Nonetheless, as SCAN and PBE are both semilocal functionals, they cannot adequately describe the van der Waals (vdW) asymptote [10,15], which requires an accurate treatment of long-range dynamical correlation effects. Incorporating SCAN and PBE with the double-hybrid schemes [38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55], the DFT-D (KS-DFT with empirical dispersion corrections) schemes [44,[82][83][84][85][86][87][88], or fully nonlocal density functionals [89][90][91] may greatly improve the accuracy of SCAN and PBE for vdW interactions.…”

“…Besides, as more exact constraints are likely to be satisfied by construction with the functionals on higher rungs of the ladder, semilocal density functionals are expected to achieve higher accuracy by climbing up the ladder at the expense of a slight increase in computational cost [7]. However, due to the lack of an accurate description of nonlocal XC effects, semilocal density functionals can yield erroneous results in situations where the self-interaction error (SIE), noncovalent interaction error (NCIE), or static correlation error (SCE) is enormous [3][4][5][6][10][11][12][13][14][15]. level theoretical data) [7].…”

Role of exact exchange in thermally-assisted-occupation density functional theory: A proposal of new hybrid schemes

“…Nonetheless, owing to the inappropriate treatment of nonlocal XC effects [12,13], KS-DFAs can perform very poorly in situations where the self-interaction error (SIE) [12][13][14][15], noncovalent interaction error (NCIE) [16][17][18], or static correlation error (SCE) [12,[19][20][21][22] is pronounced. Over the years, considerable efforts have been made to resolve the qualitative failures of KS-DFAs at a reasonable computational cost.…”

Short- and long-range corrected hybrid density functionals with the D3 dispersion corrections

“…They are reasonably accurate for the properties governed by short-range XC effects, and are computationally favorable for very large systems. Nevertheless, owing to the inadequate treatment of nonlocal XC effects [3][4][5][6]21], semilocal density functionals can perform very poorly for the problems related to the self-interaction error (SIE) [22], noncovalent interaction error (NCIE) [23][24][25], and static correlation error (SCE) [26][27][28][29][30][31][32].…”