LOBSTER: Local orbital projections, atomic charges, and chemical‐bonding analysis from projector‐augmented‐wave‐based density‐functional theory

Abstract

We present an update on recently developed methodology and functionality in the computer program LOBSTER (Local Orbital Basis Suite Towards Electronic-Structure Reconstruction) for chemical-bonding analysis in periodic systems. LOBSTER is based on an analytic projection from projector-augmented wave (PAW) densityfunctional theory (DFT) computations [J. Comput. Chem. 2013, 34, 2557, reconstructing chemical information in terms of local, auxiliary atomic orbitals and thereby opening the output of PAW-based DFT codes to chemical interpretation. We demonstrate how LOBSTER has been improved by taking into account time reversal symmetry, thereby speeding up the DFT and LOBSTER calculations by a factor of 2.Over the recent years, the functionalities have also been continually expanded, including accurate projected densities of states (DOS), crystal orbital Hamilton population (COHP) analysis, atomic and orbital charges, gross populations, and the recently introduced ᵈ-dependent COHP. The software is offered free-of-charge for non-commercial research. File list (2)download file view on ChemRxiv Manuscript.pdf (3.50 MiB) download file view on ChemRxiv Supporting_Information.pdf (647.70 KiB)

Ab initio molecular dynamics and materials design for embedded phase-change memory

“…Chemical bonding analyses using the crystal orbital overlap population (COOP) method and a projection onto local, atomcentered orbitals [48][49][50] were performed for relaxed structural snapshots of the Ge-rich amorphous phases, following an approach we have previously proposed for amorphous GeTe 46,47 . The COOP curves show no strong antibonding interaction at the Fermi level for both amorphous Ge 2 Sb 2 Te 5 and Ge 2 Sb 1 Te 2 ( Supplementary Figure 4), indicating reasonable chemical stability of the amorphous models.…”

Machine learning driven simulated deposition of carbon films: From low-density to diamondlike amorphous carbon

“…On the one hand, we estimated the force acting on the 5-c atom, predicted by LDA-DFT (the reference in the a-C GAP), as a proxy for the stability of these 5-c complexes. On the other hand, we quantify the chemical bonding nature using crystal orbital overlap population (COOP) [74] and crystal orbital Hamilton population (COHP) [75] analyses, based on a local-orbital projection scheme as implemented in LOBSTER [76][77][78]. In brief, a self-consistent electronicstructure computation in the projector-augmented wave (PAW) framework [79] is carried out, here using VASP [80,81].…”

“…The self-consistent electronic wave function is then projected onto an auxiliary, atom-centered basis of 2s and 2p orbitals (following ideas proposed in Ref. 82), and the availability of local information allows the reconstruction of energy-and orbitalresolved chemical-bonding indicators [76][77][78]. The energy integration of COOP(E) up to the Fermi level yields a measure for the electron population associated with a given bond (positive values indicating stabilization), whereas the integration of COHP(E) gives an energy value (negative values indicating stabilization) [75].…”

Predicting Nitrogen‐Based Families of Compounds: Transition‐Metal Guanidinates TCN3 (T=V, Nb, Ta) and Ortho‐Nitrido Carbonates T′2CN4 (T′=Ti, Zr, Hf)

“…For T' 2 N 2 (NCN) and T' 2 N(CN 3 ), the T'ÀN1 distance is significantly longer than the T' À N2 distance, so the existence of the isolated N 3À anion in T' 2 N 2 (NCN) and T' 2 N(CN 3 ) is quite obvious even from geometry. The strengths of the chemical bonds are directly quantified by the Integrated Crystal Orbital Hamilton Populations (ICOHP) as projected by LOBSTER, [30] plotted in Figure 4 b). For T' 2 N 2 (NCN) and T' 2 N(CN 3 ), the covalent part of the T'ÀN bonding is not too large, as expected for a metalnitrogen bond.…”