Assessment of long-range corrected density functionals for dipole polarizability calculations of MX (M = Y-Cd; X = F, Cl, Br, and I) molecules

Abstract

We present an extension of our previously published density functionals benchmarking for the static dipole polarizability calculations of 4d transition metal monohalides MX (M = Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, and Cd; X = F, Cl, Br, and I) [M. Alipour and A. Mohajeri, Mol. Phys. 109 (2011), 1439]. Based on a statistical analysis, the behaviors of five long-range corrected density functionals, CAM-B3LYP, LC-ωPBE, ωB97, ωB97X and ωB97X-D have been assessed. The high accuracy CCSD(T) methodology is used to benchmark the effect of long-range corrections in polarizability calculations. Among tested functionals, the LC-ωPBE functional is found to outperform others. Moreover, we have compared the performance of long-range corrected functionals with 42 previously tested functionals of various types including local spin density approximation (LSDA), generalized gradient approximation (GGA), meta GGA (MGGA), hybrid GGA (HGGA), and hybrid meta GGA (HMGGA). Our results show that there is a large variation in performance of various functionals in each type for calculations of the dipole polarizabilities. It has been indicated that long-range corrected functionals do not necessarily outperform older functionals, at least for the mean static dipole polarizability studied here. In particular, our extensive analysis shows that the functionals of B98, mPWIPW91, TPSSIKCIS, PBEIKCIS and B3PW91 are the best of all 47 tested density functionals. The results of this investigation can be used as a guidance to propose a new exchange-correlation functional for calculating the optical properties such as polarizability for considered molecules and also for larger transition metal systems.