Theoretical Studies of Au3+/0/- Clusters Using Density Funtional Theory

2020 ◽  
Vol 862 ◽  
pp. 94-98
Author(s):  
Kuan Yu Chen ◽  
Yi Ting Kong ◽  
Shyi Long Lee
Keyword(s):  
Molecular Orbital ◽  
Computational Result ◽  
Ground State ◽  
Equilateral Triangle ◽  
Bond Angle ◽  
Linear Structure ◽  
Stable Structure ◽  
Theoretical Studies ◽  
Inversion Barrier ◽  
Ground State Geometry

In this study, the PW91PW91 method with LANL2DZ level was carried out to settle the dispute about the most stable structure of Au3+/0/-. Molecular orbital analyses and Walsh diagram were adopted to rationalize our computational result about the ground state geometry of Au3+/0/-. Our results show that the most stable geometry of Au3 is bent structure (C2v) with bond angle 146.0°. The less stable structure is equilateral triangle structure (D3h) with relative energies of 1.74 eV. The D3h structure possesses multiplicity 4 while the C2v structure 2. In addition, the most stable geometry of Au3+ and Au3- are equilateral triangle structure (D3h) and linear structure (D∞h), respectively. The preference of geometric change can be rationalized simply by using Walsh diagram. Besides, the linear structure of Au3 is found to be transition states (TS) of inversion of B-Au3. The inversion barrier is estimated to be 0.04 eV.

scholarly journals A Class of Non-Kekulé Molecules with Low Excitation Energies

2007 ◽  
Vol 62 (11) ◽  
pp. 1433-1436
Author(s):  
Fritz Dietz ◽  
Nedko Drebov ◽  
Nikolai Tyutyulkov
Keyword(s):  
Molecular Orbital ◽  
Ground State ◽  
Excitation Energies ◽  
Triplet Ground State ◽  
Molecular Systems ◽  
Structural Principle

A class of non-Kekulé molecular systems with a new structural principle and low excitation energies or with a triplet ground state was investigated theoretically. The systems consist of a non-Kekulé monoradical, possessing a non-bonding molecular orbital linked in a specific way to another monoradical.

REVIEW ON THEORETICAL STUDIES OF SUPERHEAVY NUCLEI

2006 ◽  
Vol 15 (07) ◽  
pp. 1587-1599 ◽  
Author(s):  
ZHONGZHOU REN ◽  
DINGHAN CHEN ◽  
CHANG XU
Keyword(s):  
Ground State ◽  
Large Mass ◽  
Mass Region ◽  
Superheavy Nuclei ◽  
Theoretical Studies ◽  
Shape Coexistence ◽  
Good Test ◽  
Α Decay ◽  
The Stability ◽  
Theoretical Results

Superheavy elements have provided a good test of the validity of both nuclear structure models and nuclear decay models in a large mass region. We firstly review the recent progress on theoretical studies of superheavy nuclei. Emphasis is placed on the structure and decay of superheavy nuclei. Then theoretical results of odd-odd nuclei with Z = 109 - 115 are presented and discussed. It is clearly demonstrated that there is shape coexistence for the ground state of many superheavy nuclei from different models and many superheavy nuclei are deformed. In some cases superdeformation can become the ground state of superheavy nuclei and it is important for future studies of superheavy nuclei. This can lead to the existence of low-energy isomers in the superheavy region and it plays an important role for the stability of superheavy nuclei. As α-decay and spontaneous fission plays a crucial role for identifications of new elements, we also review some typical models of α-decay half-lives and spontaneous fissions half-lives. Some new views on superheavy nuclei are presented.

Orbital-based Descriptions of Electron Configurations, Ionization, Excitation, and Bonding

2020 ◽  
pp. 188-216
Author(s):  
Jochen Autschbach
Keyword(s):  
Molecular Orbital ◽  
Ground State ◽  
Orbital Energy ◽  
Chemical Bonds ◽  
Theory Construction ◽  
Electronic Excitations ◽  
Energy Gaps ◽  
Koopmans Theorem ◽  
Total Energies ◽  
Ground State Electron

This chapter deals with quantitative aspects of molecular orbital (MO) theory: Construction of an orbital diagram, bonding and antibonding overlap, Koopmans’ theorem, orbital energies versus total energies, an explanation of the unintuitive ground state electron configurations seen for some neutral transition metals, and a discussion of orbital energy gaps versus electronic excitations and other observable energy gaps. Localized MOs show the chemical bonds expected from the Lewis structure more readily than the canonical orbitals obtained from solving the SCF equations. It is shown that the delocalization of localized, not the canonical, MOs shows whether a system is delocalized. Algorithms by which to obtain localized MOs are sketched.

Are Tetra[gold(I)]phosphonium Cations [(LAu)4P]+ Non-obedient to the LeBel-van’t Hoff Rule?

2008 ◽  
Vol 63 (7) ◽  
pp. 853-859 ◽  
Author(s):  
Hubert Schmidbaur
Keyword(s):  
Ground State ◽  
Central Element ◽  
Theoretical Studies ◽  
Tetrahedral Structure ◽  
Pyramidal Structure ◽  
Onium Salts ◽  
Central Elements ◽  
Aurophilic Interactions ◽  
Molecular And Electronic Structure ◽  
Phosphonium Cations

Recent theoretical studies of the molecular and electronic structure of tetra[(phosphine)gold(I)]- phosphonium cations, [(H3PAu)4P]+, gave contradictory results favoring either a classical tetrahedral or a unique square-pyramidal structure of the PAu4 unit. A tetrahedral structure had previously been confirmed for the corresponding ammonium cations [(Ph3PAu)4N]+, while a square-pyramidal structure was discovered for the corresponding arsonium cations [(Ph3PAu)4As]+, but there is as yet no unequivocal experimental evidence for the structure of phosphonium cations like [(Ph3PAu)4P]+ in an innocent environment. - In this account the structural chemistry of this class of onium salts and related species is reviewed. The data accumulated to date provide virtually compelling evidence that the phosphonium cations should have a ground state with a square pyramidal PAu4 core unit, provided that no external constraints are imposed. For large central elements (P, As), aurophilic interactions appear to drive the reorganization from tetrahedral to square-pyramidal skeletons in which a maximum number of short Au---Au contacts can be maintained. For the small central element N, similar interactions are already realized in the tetrahedral structure.

Electronic spectrum of D2O+

1987 ◽  
Vol 65 (7) ◽  
pp. 739-752 ◽  
Author(s):  
H. Lew ◽  
R. Groleau
Keyword(s):  
Bond Length ◽  
Ground State ◽  
Simple Formula ◽  
Bond Angle ◽  
Spin Rotation ◽  
Type B ◽  
Infrared Band ◽  
Asymmetric Rotor ◽  
Linear Molecules ◽  
Van Vleck

An analysis of 15 bands of the [Formula: see text] system of D2O+ is given. All assigned lines are tabulated. The rotational structures of the [Formula: see text], 1, and 3 levels of the ground state are fitted to the Watson asymmetric rotor Hamiltonian with added spin-rotation terms. For the upper state, the rotational structures of various substates are expressed: for [Formula: see text], in terms of a simple formula for linear molecules; and for [Formula: see text], 2, and 3, in terms of a modified Hill – Van Vleck formula given by Jungen, Hallin, and Merer. From the rotational constants of the ground state, term values are calculated and a small portion of a Type-B infrared band is derived. Some predicted microwave lines are also given. The bond length and bond angle of the molecule in the ground state (ν = 0) are r0 = 0.9987 ± 0.0002 Å and θ0 = 110.17 ± 0.02 deg.

Sign in / Sign up

Export Citation Format

Share Document