Related Experiment Video
Updated: May 31, 2026

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
First-principles calculation of the conductance of a single 4,4 bipyridine molecule
Shimin Hou1, Jiaxing Zhang, Rui Li
1Department of Electronics, Peking University, Beijing 100871, People's Republic of China.
Abstract:
The conductance of a single 4,4 bipyridine (44BPD) molecule connected to two gold electrodes is calculated using a density functional theory based Green function method. The atomic geometry of such a molecular junction is constructed from the optimized structure of a gold trimer-44BPD-gold trimer complex. Resonant conduction is the main feature of its transport properties. The magnitude of the transmission coefficient at the Fermi level is determined to be T = 1.01 × 10(-2), which is in excellent agreement with the experimental value. The dependence of the transmission on the Au-N bond length and the torsion angle is also discussed.
Related Concept Videos
Debye–Huckel–Onsager Conductance Equation
π Molecular Orbitals of 1,3-Butadiene
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
Predicting Molecular Geometry
VSEPR Theory and the Effect of Lone Pairs
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
VSEPR Theory and the Basic Shapes

