#hyperpolarizability
Every note tagged #hyperpolarizability, newest first — or browse the full archive.
Molecules as circuits — a chromophore as an RLC resonator
An absorption energy gap is a resonant frequency, a transition dipole is charge sloshing across a capacitor, and a linewidth is a resistance — so a dye molecule is literally a driven RLC circuit. This post makes the analogy pay its way, pinning every circuit element to a number from a real chromophore I synthesized, then shows the three places the model quietly stops describing the physics: the hyperpolarizability, the quantum interference in the wiring, and the many-body order that actually sets device performance.
One matrix element, two experiments: molar absorptivity and the Pockels effect
A companion to the molar-absorptivity post. The absolute height of an absorption band, the refractive index, and the electro-optic coefficient of a poled material are three readouts of one quantity — the transition dipole. Normalizing every spectrum to 1 throws that quantity away. This traces the same matrix element from Beer's law through the two-level model to the Pockels effect, with worked numbers.
Mathematical Framework for Hyperpolarizability Calculations
A detailed explanation of the mathematical principles underlying hyperpolarizability calculations
Quantum Chemical Calculations of Hyperpolarizability - Setup and Initial Results
A detailed walkthrough of setting up computational environment for calculating hyperpolarizabilities of Group 4A elements
Calculating Atomic Polarizabilities of Group 14 Elements Using Psi4 - A Finite Field Approach
An experimental study calculating polarizabilities of Group 14 elements using Psi4's finite field method, with results for C, Si, and Ge, and insights into limitations for heavier elements.