Stephan Niklaus Steinmann

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Density functional approximations fail to provide a consistent description of weak molecular interactions arising from small electron density overlaps. A simple remedy to correct for the missing interactions is to add a posteriori an attractive energy term ...

Scalar fields provide an intuitive picture of chemical bonding. In particular, the electron localization function (ELF) has proven to be highly valuable in interpreting a broad range of bonding patterns. The discrimination between enhanced or reduced elect ...

This thesis introduces original formalisms to achieve an accurate description of dispersion interactions within the framework of density functional theory. The presented research focuses on two specific objectives related to density functional approximatio ...

As the simplest variant of the valence bond (VB) theory, the block-localized wave function (BLW) method defines the intermediate electron-localized state self-consistently at the DFT level and can be used to explore the nature of intermolecular interaction ...

The treatment of dispersion interactions is ubiquitous but computationally demanding for seamless ab initio approaches. A highly popular and simple remedy consists in correcting for the missing interactions a posteriori by adding an attractive energy term ...

The ring strain energies of carbomeric-cycloalkanes (molecules with one or more acetylene spacer units placed into carbon single bonds) are assessed using a series of isodesmic, homodesmotic, and hyperhomodesmotic chemical equations. Isodesmic bond separat ...

Despite the widespread use and numerous successful applications of density functional theory, descriptions of hydrocarbon reaction energies remain problematic. Illustrative examples include large underestimation of energies associated with alkane bond sepa ...

The long-standing mystery surrounding the peculiar electronic structure of norbornene and its derivatives is revealed by the direct comparisons of their properties with those of reference analogues with localized double bonds (i.e. Lewis structures). Our b ...

Neutral and charged assemblies of π-conjugated molecules span the field of organic electronics. Electronic structure computations can provide valuable information regarding the nature of the intermolecular interactions within molecular precursors to organi ...

Clusters in the (Be, B, C)@Si-n((0,1,2+)) (n = 6-10) series, isoelectronic to Si-n(2-), present multiple symmetric structures, including rings, cages and open structures, which the doping atom stabilizes using contrasting bonding mechanisms. The most strik ...

Bond separation reactions of highly branched alkanes are used to assess (de)stabilizing interactions associated with various 1,3-nonbonded substituent patterns. While n- and singly methylated alkanes show positive bond separation energies (BSEs), which inc ...

The dye disodium 3,4:3’,4’-bibenzo[b]thiophene-2,2’-disulfonate can be used as molecular probe for the fluorimetric detection of caffeine in aqueous solution. The fluorescence response is attributed to non-covalent interactions of caffeine with the dye in ...

Chemists recurrently utilize "fuzzy'' chemical concepts (e.g. atomic charges, the chemical bond, strain, aromaticity, branching, etc.), which lack unique quantitative assessments but, nonetheless, are frequently employed as tools for understanding the intr ...

A simple method for computing accurate density-dependent dispersion coefficients is presented. The dispersion coefficients are modeled by a generalized gradient-type approximation to Becke and Johnson's exchange hole dipole moment formalism. Our most cost- ...

Organic electronic materials remarkably illustrate the importance of the "weak" dispersion interactions that are neglected in the most cost-efficient electronic structure approaches. This work introduces a fast atom-pairwise dispersion correction, dDMC tha ...

The description of ground state charge-transfer complexes is highly challenging. Illustrative examples include large overestimations of charge-transfer by local and semi-local density functional approximations as well as inaccurate binding energies. It is ...

The commercially available fluorescence dye 8-hydroxypyrene-1,3,6-trisulfonate (HPTS) can be used as a selective molecular probe for the detection of caffeine in aqueous solution. ...

Density functional approximations fail to provide an accurate treatment of weak interactions. More recent, but not readily available functionals can lead to significant improvements. A simple alternative to correct for the missing weak interactions is to a ...

Stephan Niklaus Steinmann

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System-Dependent Density Based Dispersion Correction

How do electron localization functions describe p-electron delocalization?

Understanding and Minimizing Density Functional Failures Using Dispersion Corrections

Dispersion-Corrected Energy Decomposition Analysis for Intermolecular Interactions Based on the BLW and dDXDM Methods

How Important is Self-Consistency for the dDsC Density Dependent Dispersion Correction?

How Strained are Carbomeric-Cycloalkanes?

Overcoming systematic DFT errors for hydrocarbon reaction energies

The norbornene mystery revealed

Exploring the Limits of DFT for Interaction Energies of Molecular Precursors to Organic Electronics

How are small endohedral silicon clusters stabilized?

Branched Alkanes Have Contrasting Stabilities

A ratiometric fluorescence sensor for caffeine

Quantification of "Fuzzy" Chemical Concepts: A Computational Perspective

A generalized-gradient approximation exchange hole model for dispersion coefficients

A fast charge-dependent atom-pairwise dispersion correction for DFTB3

Why are the Interaction Energies of Charge-Transfer Complexes Challenging for DFT?

Direct Assessment of Electron Delocalization on NMR Chemical Shifts

Unified Inter- and Intramolecular Dispersion Correction Formula for Generalized Gradient Approximation Density Functional Theory

Fluorescence sensing of caffeine in water with polysulfonated pyrenes

A Density Dependent Dispersion Correction