When Do Interacting Atoms Form a Chemical Bond? Spectroscopic Measurements and Theoretical Analyses of Dideuteriophenanthrene

2009 ◽  
Vol 48 (14) ◽  
pp. 2592-2595 ◽  
Author(s):  
Stefan Grimme ◽  
Christian Mück-Lichtenfeld ◽  
Gerhard Erker ◽  
Gerald Kehr ◽  
Huadong Wang ◽  
...  
Author(s):  
R. J. Wilson ◽  
D. D. Chambliss ◽  
S. Chiang ◽  
V. M. Hallmark

Scanning tunneling microscopy (STM) has been used for many atomic scale observations of metal and semiconductor surfaces. The fundamental principle of the microscope involves the tunneling of evanescent electrons through a 10Å gap between a sharp tip and a reasonably conductive sample at energies in the eV range. Lateral and vertical resolution are used to define the minimum detectable width and height of observed features. Theoretical analyses first discussed lateral resolution in idealized cases, and recent work includes more general considerations. In all cases it is concluded that lateral resolution in STM depends upon the spatial profile of electronic states of both the sample and tip at energies near the Fermi level. Vertical resolution is typically limited by mechanical and electronic noise.


1989 ◽  
Vol 86 ◽  
pp. 853-859 ◽  
Author(s):  
Federico Moscardó ◽  
José Pérez-Jordá ◽  
Emilio San-Fabián

2007 ◽  
Vol 14 (3) ◽  
pp. 257-268 ◽  
Author(s):  
Xiaomin Wu ◽  
WanTian Dai ◽  
XiaoFeng Shan ◽  
Weicheng Wang ◽  
LiMing Tang

2020 ◽  
Author(s):  
Gabriel Freire Sanzovo Fernandes ◽  
Leonardo dos Anjos Cunha ◽  
Francisco Bolivar Correto Machado ◽  
Luiz Ferrão

<p>Chemical bond plays a central role in the description of the physicochemical properties of molecules and solids and it is essential to several fields in science and engineering, governing the material’s mechanical, electrical, catalytic and optoelectronic properties, among others. Due to this indisputable importance, a proper description of chemical bond is needed, commonly obtained through solving the Schrödinger equation of the system with either molecular orbital theory (molecules) or band theory (solids). However, connecting these seemingly different concepts is not a straightforward task for students and there is a gap in the available textbooks concerning this subject. This work presents a chemical content to be added in the physical chemistry undergraduate courses, in which the framework of molecular orbitals was used to qualitatively explain the standard state of the chemical elements and some properties of the resulting material, such as gas or crystalline solids. Here in Part 1, we were able to show the transition from Van der Waals clusters to metal in alkali and alkaline earth systems. In Part 2 and 3 of this three-part work, the present framework is applied to main group elements and transition metals. The original content discussed here can be adapted and incorporated in undergraduate and graduate physical chemistry and/or materials science textbooks and also serves as a conceptual guide to subsequent disciplines such as quantum chemistry, quantum mechanics and solid-state physics.</p>


2014 ◽  
Vol 13 (8) ◽  
pp. 1965-1970 ◽  
Author(s):  
Spiru Paraschiv ◽  
Lizica Simona Paraschiv ◽  
Ion V. Ion

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