Development and assessment of a short-range meta-GGA functional

Abstract

Short-range DFT/long-range ab initio methods allow for a combination of the weak basis-set dependency of DFT with an accurate ab initio treatment of long-range effects like van der Waals interaction. In order to improve existing short-range LDA and GGA density functionals, we developed a TPSS-like short-range meta-GGA exchange-correlation functional and checked its performance in long-range CCSD(T) calculations for thermodynamical properties of the G2 set of molecules.

Basis convergence of range-separated density-functional theory

“…The strategy of range-separated DFT consists in separating the Coulomb electron-electron interaction into long-range and shortrange components, and treating the long-range part by an explicit many-body wave-function method and the short-range part by a density-functional approximation. In particular, for describing systems with van der Waals dispersion interactions, it is appropriate to use methods based on many-body perturbation theory for the longrange part such as second-order perturbation theory [4][5][6][7][8][9][10][11][12][13][14][15][16], coupled-cluster theory [17][18][19][20][21], or random-phase approximations [22][23][24][25][26][27][28][29][30][31][32][33][34].…”

Range-separated double-hybrid density-functional theory applied to periodic systems

“…Future developments of range-separated DFT approaches for solids might include the implementation of other flavors of the methods (such as different short-range density functionals 115 or different long-range electron correlation methods 116,117 ). In particular, the notorious overestimation of dispersion by MP2 in highly polarizable systems, which can affect, as observed in this work, also the range-separated double-hybrids employing MP2 as the long-range model, can be cured by substituting the latter with approximate coupledcluster models, containing only the low-order slowly decaying terms.…”

Excitation energies along a range-separated adiabatic connection

“…This constant must be exactly compensated by the longrange Hartree-exchange-correlation potential in Eq. (13), so that its first-order term in µ must also be 2(N − 1)µ/ √ π. The expansion of v lr,µ Hxc (r) therefore takes the form…”

“…Several short-range density-functional approximations have been developed [1,4,[8][9][10][11][12][13] and a diverse range of approaches for calculating the ground state of the long-range interacting Hamiltonian have been explored. To aid in the description of static (or strong) correlation effects, which are poorly treated by standard density functionals, configuration-interaction [1,4,7,[14][15][16][17], multiconfiguration self-consistent-field (MCSCF) [18][19][20], density-matrix functional theory (DMFT) [21][22][23], and constrained-pairing mean-field theory [24,25] descriptions of the long-range interacting systems have been employed.…”

“…To aid in the description of static (or strong) correlation effects, which are poorly treated by standard density functionals, configuration-interaction [1,4,7,[14][15][16][17], multiconfiguration self-consistent-field (MCSCF) [18][19][20], density-matrix functional theory (DMFT) [21][22][23], and constrained-pairing mean-field theory [24,25] descriptions of the long-range interacting systems have been employed. To treat van der Waals interactions, second-order perturbation theory [26][27][28][29][30][31][32][33][34][35][36][37], coupled-cluster theory [11,13,[38][39][40], and random-phase approximations [41][42][43][44][45][46][47][48][49][50][51] have been used successfully.…”