Track papers across labs, topics, and trends.
Search papers, labs, and topics across Lattice.
This paper investigates the accuracy of the exchange-hole dipole moment (XDM) model with two different damping functions, Becke-Johnson (BJ) and Z-damping, in predicting exfoliation energies and lattice constants of layered materials. It demonstrates that both XDM(BJ) and XDM(Z) capture the proper asymptotic behavior at long range, with XDM(Z) being assessed on the LM26 benchmark for the first time. Crucially, the inclusion of three-body interactions via the Axilrod-Teller-Muto (ATM) term further improves the computed exfoliation energies for both XDM variants, achieving state-of-the-art performance on the LM26 benchmark using semi-local functionals.
Three-body interactions are the secret sauce for achieving unprecedented accuracy in predicting layered-material exfoliation energies with semi-local DFT functionals.
Accurate predictions of exfoliation energies and lattice constants of layered materials hinge on a correct description of London dispersion physics. Modern a posteriori dispersion corrections in density-functional theory (DFT), such as the exchange-hole dipole moment (XDM) model, capture the proper asymptotic behaviour at long range while making use of damping functions to prevent unphysical divergence at short range. In the united-atom limit, the dispersion energy is damped to a finite, non-zero value by both the canonical Becke--Johnson (BJ) damping function and the new Z-damping function. XDM(BJ) has previously demonstrated exceptional accuracy for modelling layered materials, such as in the LM26 benchmark, which includes graphite, hexagonal boron nitride, lead(II) oxide, and transition-metal dichalcogenides. This work presents the first assessment of XDM(Z) on the same benchmark. We also show that inclusion of three-body interactions via the Axilrod--Teller--Muto (ATM) term further improves the computed exfoliation energies for both XDM(BJ) and XDM(Z), yielding the best performance achieved on LM26 using semi-local functionals to date.