AIMLDM: A program to generate and analyze electron localization–delocalization matrices (LDMs)

Sumar, Ismat; Cook, Robert P.; Ayers, Paul W.; Matta, Chérif F.

doi:10.1016/j.comptc.2015.07.014

Cited by 25 publications

(13 citation statements)

References 26 publications

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“…An important result from QTAIM is the delocalization index, δ 143,149–153,163–165 , which is a measure of covalent bond order 163–165 . It is this property that can be evaluated for any pair of atomic basins in molecular systems or in crystals even when there is no evidence for a bond path and a (3, −1) bcp between them.…”

Section: Resultsmentioning

confidence: 99%

Significance of hydrogen bonding and other noncovalent interactions in determining octahedral tilting in the CH3NH3PbI3 hybrid organic-inorganic halide perovskite solar cell semiconductor

Varadwaj

Marques

Yamashita

2019

Sci Rep

111

100

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The CH3NH3PbI3 (methylammonium lead triiodide) perovskite semiconductor system has been viewed as a blockbuster research material during the last five years. Because of its complicated architecture, several of its technological, physical and geometrical issues have been examined many times. Yet this has not assisted in overcoming a number of problems in the field nor in enabling the material to be marketed. For instance, these studies have not clarified the nature and type of hydrogen bonding and other noncovalent interactions involved; the origin of hysteresis; the actual role of the methylammonium cation; the nature of polarity associated with the tetragonal geometry; the unusual origin of various frontier orbital contributions to the conduction band minimum; the underlying phenomena of spin-orbit coupling that causes significant bandgap reduction; and the nature of direct-to-indirect bandgap transition features. Arising from many recent reports, it is now a common belief that the I···H–N interaction formed between the inorganic framework and the ammonium group of CH3NH3+ is the only hydrogen bonded interaction responsible for all temperature-dependent geometrical polymorphs of the system, including the most stable one that persists at low-temperatures, and the significance of all other noncovalent interactions has been overlooked. This study focussed only on the low temperature orthorhombic polymorph of CH3NH3PbI3 and CD3ND3PbI3, where D refers deuterium. Together with QTAIM, DORI and RDG based charge density analyses, the results of density functional theory calculations with PBE with and without van der Waals corrections demonstrate that the prevailing view of hydrogen bonding in CH3NH3PbI3 is misleading as it does not alone determine the a−b+a− tilting pattern of the PbI64− octahedra. This study suggests that it is not only the I···H/D–N, but also the I···H/D–C hydrogen/deuterium bonding and other noncovalent interactions (viz. tetrel-, pnictogen- and lump-hole bonding interactions) that are ubiquitous in the orthorhombic CH3NH3PbI3/CD3ND3PbI3 perovskite geometry. Their interplay determines the overall geometry of the polymorph, and are therefore responsible in part for the emergence of the functional optical properties of this material. This study also suggests that these interactions should not be regarded as the sole determinants of octahedral tilting since lattice dynamics is known to play a critical role as well, a common feature in many inorganic perovskites both in the presence and the absence of the encaged cation, as in CsPbI3/WO3 perovskites, for example.

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Section: Resultsmentioning

confidence: 99%

Significance of hydrogen bonding and other noncovalent interactions in determining octahedral tilting in the CH3NH3PbI3 hybrid organic-inorganic halide perovskite solar cell semiconductor

Varadwaj

Marques

Yamashita

2019

Sci Rep

111

100

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“…DI is usually calculated by considering the mutual overlap of MOs across two atomic basins, and is therefore a very good link between MO‐theory and Quantum Chemical Topology (QCT) . The full sets of LIs and DIs in a molecule have been combined as localization–delocalization matrices (LDMs) by Matta and coworkers This approach has been used to understand the complex network of localized and delocalized contributions to atomic populations . While an LDM provides a very valuable condensed overview of ED localization and delocalization at an atomic level, it does not provide valuable chemical information inherent in the real‐space distributions of correlated ED.…”

Section: Theoretical Background and Developmentmentioning

confidence: 99%

FALDI‐based decomposition of an atomic interaction line leads to 3D representation of the multicenter nature of interactions

2018

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Atomic interaction lines (AILs) and the QTAIM's molecular graphs provide a predominantly two-center viewpoint of interatomic interactions. While such a bicentric interpretation is sufficient for most covalent bonds, it fails to adequately describe both formal multicenter bonds as well as many non-covalent interactions with some multicenter character. We present an extension to our Fragment, Atomic, Localized, Delocalized and Interatomic (FALDI) electron density (ED) decomposition scheme, with which we can measure how any atom-pair's delocalized density concentrates, depletes or reduces the electron density in the vicinity of a bond critical point. We apply our method on five classical bonds/interactions, ranging from formal either two- or three-center bonds, a non-covalent interaction (an intramolecular hydrogen bond) to organometallic bonds with partial multicenter character. By use of 3D representation of specific atom-pairs contributions to the delocalized density we (i) fully recover previous notion of multicenter bonding in diborane and predominant bicentric character of a single covalent CC bond, (ii) reveal a multicenter character of an intramolecular H-bond and (iii) illustrate, relative to a Schrock carbene, a larger degree of multicenter MC interaction in a Fischer carbene (due to a presence of a heteroatom), whilst revealing the holistic nature of AILs from multicenter ED decomposition. © 2018 Wiley Periodicals, Inc.

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“…The electron localization-delocalization matrices (LDMs) are a class of electronic molecular descriptors used to quantify molecular similarity. [58][59][60][61][62] LDMs are used here as a measure of electronic distribution similarity to compare the three dications.…”

Section: Methodsmentioning

confidence: 99%

Bonding and metastability for Group 12 dications

2020

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AIMLDM: A program to generate and analyze electron localization–delocalization matrices (LDMs)

Cited by 25 publications

References 26 publications

Significance of hydrogen bonding and other noncovalent interactions in determining octahedral tilting in the CH3NH3PbI3 hybrid organic-inorganic halide perovskite solar cell semiconductor

Significance of hydrogen bonding and other noncovalent interactions in determining octahedral tilting in the CH3NH3PbI3 hybrid organic-inorganic halide perovskite solar cell semiconductor

FALDI‐based decomposition of an atomic interaction line leads to 3D representation of the multicenter nature of interactions

Bonding and metastability for Group 12 dications

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