Near-infrared radiation absorption properties of covellite (CuS) using first-principles calculations

A refinement of the crystal structure of covellite, CuS

The crystal structure of covellite has been refined, based on counter intensity data, to R=3.9,°-6', using a crystal from Kosaka mine: P63/mmc, a=3.976(1), c=16.382(5)'\, Z=6. The structure proposed by Oftedal (Zeits. Krist., 83, 9-25, 1932) was confirmed. The S-S distance of the S2 groups in the structure is 2.086(7)'\, the Cu-S distance in the CUS3 triangles 2.1915(4)'\, and the mean Cu-S dis...

Optical Properties of Antiferroelectric Cs2Nb4O11: Absorption Spectra and First-Principles Calculations

Water vapor absorption of visible and near infrared radiation.

Water vapor error function absorption coefficients for visible and near ir radiation have been recalculated from experimental transmission data. The error function absorption coefficients and the resulting transmissions as a function of precipitable water vapor are tabulated for wavelengths from 0.2 micro to 1.3 micro. Comparisons are made between computed and measured spectral transmittances.

Infrared Absorption Spectrum of Brushite from First Principles

Brushite, CaHPO4·2H2O, is a crystalline hydrated acidic form of calcium phosphate that occurs in both physiological and pathological biomineralization processes. Additionally, it is biocompatible in humans. Several groups have investigated the experimental Fourier transform infrared vibrational spectrum of brushite. These investigations have led to a longstanding debate concerning the correct a...

First Principles Calculations

Calculations of the linestrengths and transition frequencies of the forbidden pure rotational spectrum of Hz in the vibrationally excited v2 state are presented. These transitions occur in the far-infrared region, and their observation may be complicated by vi u2 difference transitions. Examples of these are also given. Forbidden rovibrational transition frequencies and linestrengths have also ...