Themed collection Developments in Density Functional Theory
Editorial for PCCP themed issue “Developments in Density Functional Theory”
This issue provides an overview of the state-of-the-art of DFT, ranging from mathematical and software developments, via topics in chemical bonding theory, to all kinds of molecular and material properties. Through this issue, we also celebrate the enormous contributions that Evert Jan Baerends has made to this field.
How molecular is the chemisorptive bond?
Scaling rules differ for early and late transition metals. Their electronic structure and topological bond analysis are shown.
Introducing a closed system approach for the investigation of chemical steps involving proton and electron transfer; as illustrated by a copper-based water oxidation catalyst
We present an ab initio molecular dynamics approach to characterize proton-coupled electron transfer catalytic steps and identify the preferred reaction mechanism.
First hyperpolarizability of para-aminoaniline induced by a variety of gold nano particles
Molecules exposed to an electromagnetic field due to the presence of nearby nanoparticles are known to be affected.
Revisiting an old concept: the coupled oscillator model for VCD. Part 2: implications of the generalised coupled oscillator mechanism for the VCD robustness concept
The generalised coupled oscillator (GCO) mechanism implies that the stability of the computed VCD sign should be assigned by monitoring the uncertainties in the relative orientation of the GCO fragments and in the nuclear displacement vectors, i.e. not the magnitude of the dissymmetry factor.
Revisiting an old concept: the coupled oscillator model for VCD. Part 1: the generalised coupled oscillator mechanism and its intrinsic connection to the strength of VCD signals
This work reports the development of a generalised coupled oscillator expression for VCD that is exact within the harmonic approximation and is applicable to all types of normal modes, regardless whether the considered molecule is symmetric or asymmetric.
An ab initio molecular dynamics study of D2 dissociation on CO-precovered Ru(0001)
In dynamics studies of hydrogen dissociation on CO pre-covered Ru(0001) the simulation cell size is important for describing energy exchange.
The role of alkali metal cations in the stabilization of guanine quadruplexes: why K+ is the best
The desolvation and size of monovalent alkali metal ions are of equal importance for the cation affinity of guanine quadruplexes.
Constrained subsystem density functional theory
Constrained Subsystem Density Fucntional Theory (CSDFT) allows to compute diabatic states for charge transfer reactions using the machinery of the constrained DFT method, and at the same time is able to embed such diabatic states in a molecular environment via a subsystem DFT scheme.
Magnetic properties with multiwavelets and DFT: the complete basis set limit achieved
Multiwavelets are emerging as an attractive alternative to traditional basis sets such as Gaussian-type orbitals and plane waves.
Performance of polarisation functionals for linear and nonlinear optical properties of bulk zinc chalcogenides ZnX (X = S, Se, and Te)
We calculated the frequency dependent macroscopic dielectric function and second-harmonic generation of cubic ZnS, ZnSe and ZnTe within time-dependent density-polarisation functional theory.
A broken-symmetry density functional study of structures, energies, and protonation states along the catalytic O–O bond cleavage pathway in ba3 cytochrome c oxidase from Thermus thermophilus
The [Fea3, CuB] dinuclear center states along the O–O bond cleavage pathway in ba3 cytochrome c oxidase have been studied using broken-symmetry density functional calculations.
New approaches for the calibration of exchange-energy densities in local hybrid functionals
A new derivation of semi-local calibration functions is proposed, to ameliorate the gauge problem of exchange-energy densities in local hybrid functionals.
Analytical gradients for excitation energies from frozen-density embedding
Analytical excitation-energy gradients from frozen-density embedding–time-dependent density functional theory are derived and implemented, which are important for photochemistry in complex systems.
Time-dependent Dyson orbital theory
Probabilities of single ionization channels or double and multiple simultaneous ionization can be determined from exact master equations for time-dependent Dyson orbitals.
Numerical density-to-potential inversions in time-dependent density functional theory
We present an unconditionally stable TDDFT inversion algorithm based on a constrained partial differential equation optimization framework and capable of recovering highly singular potentials.
Effect of metallation, substituents and inter/intra-molecular polarization on electronic couplings for hole transport in stacked porphyrin dyads
Hole transport properties for stacked porphyrins are analyzed with density functional theory.
Reduced density matrix embedding. General formalism and inter-domain correlation functional
An embedding method for a one-electron reduced density matrix (1-RDM) is proposed.
Planar vs. three-dimensional X62−, X2Y42−, and X3Y32− (X, Y = B, Al, Ga) metal clusters: an analysis of their relative energies through the turn-upside-down approach
Despite the fact that B and Al belong to the same group 13 elements, the B62− cluster prefers the planar D2h geometry, whereas Al62− favours the Oh structure, which is caused by orbital interactions.
Time-dependent density functional theory beyond Kohn–Sham Slater determinants
Different choices of initial Kohn Sham wavefunction shape the time-dependent exchange–correlation potential.
Origin of the step structure of molecular exchange–correlation potentials
The step structure of exact exchange–correlation potentials is linked to the properties of the average local electron energy (ALEE).
Frozen-density embedding theory with average solvent charge densities from explicit atomistic simulations
Besides molecular electron densities obtained within the Born–Oppenheimer approximation (ρB(r)) to represent the environment, the ensemble averaged density (〈ρB〉(r)) is also admissible in frozen-density embedding theory (FDET) [Wesolowski, Phys. Rev. A, 2008, 77, 11444].
The S66x8 benchmark for noncovalent interactions revisited: explicitly correlated ab initio methods and density functional theory
The S66x8 dataset for noncovalent interactions of biochemical relevance has been re-examined by means of CCSD(F12*)(T), DFT, and SAPT methods.
Using the GVB Ansatz to develop ensemble DFT method for describing multiple strongly correlated electron pairs
Ensemble density functional theory (DFT) furnishes a rigorous theoretical framework for describing the non-dynamic electron correlation arising from (near) degeneracy of several electronic configurations.
The adiabatic strictly-correlated-electrons functional: kernel and exact properties
We investigate a number of formal properties of the adiabatic strictly-correlated electrons (SCE) functional, relevant for time-dependent potentials and for kernels in linear response time-dependent density functional theory.
External orthogonality in subsystem time-dependent density functional theory
We present a subsystem TDDFT method which maintains inter-subsystem orbital orthogonality.
Kohn–Sham calculations of NMR shifts for paramagnetic 3d metal complexes: protocols, delocalization error, and the curious amide proton shifts of a high-spin iron(II) macrocycle complex
Ligand chemical shifts (pNMR shifts) are analyzed using DFT. A large difference in the amide proton shifts of a high-spin Fe(II) complex arises from O → Fe dative bonding which only transfers β spin density to the metal.
No need for external orthogonality in subsystem density-functional theory
Contrary to previous claims, there is no formal need for enforcing external orthogonality in subsystem density-functional theory.
Avoiding the 4-index transformation in one-body reduced density matrix functional calculations for separable functionals
One of the major computational bottlenecks in one-body reduced density matrix functional is the evaluation of the approximate functionals due to a 4-index transformation. For separable functionals, the 4-index transformation can be avoided which leads to a significant better scaling.
4-Component relativistic calculations of L3 ionization and excitations for the isoelectronic species UO22+, OUN+ and UN2
4-Component relativistic calculations explore uranium 2p3/2 ionization and excitation in the isoelectronic series UO22+, OUN+ and UN2.
Extension of the interacting quantum atoms (IQA) approach to B3LYP level density functional theory (DFT)
The recovery of the total molecular energy from the IQA energy components for a B3LYP wave function is now possible.
A computationally efficient double hybrid density functional based on the random phase approximation
A new double hybrid density functional (PWRB95) based on GGA orbitals and RPA is presented and its performance is investigated compared to standard DFT and wavefunction methods.
About this collection
This themed issue highlights state-of-the-art density functional theory (DFT), ranging from mathematical development of the formalism, via software development and development of bonding and reactivity models through applications in physical, (in)organic, and biological/supramolecular chemistry. This issue coincides with the 70th birthday of Prof. Evert Jan Baerends, who has made a significant contribution to the field, and is guest edited by Robert van Leeuwen, Johannes Neugebauer, Lucas Visscher and F. Matthias Bickelhaupt.