NIST logo

Atomic and Molecular Data


Thermophysical Properties of Gases Used in the Semiconductor Industry

J. Hurly and K. Gillis
NIST is measuring the thermophysical properties of the process gases, the "surrogate" gases, and binary mixtures of process and carrier gases. The process gases are used in chemical vapor deposition (CVD) and the surrogate gases are used to calibrate mass flow controllers (MFCs). The results will be disseminated in this data base providing the heat capacity, thermal conductivity, viscosity, and the virial coefficients for the virial equation of state providing the pressure-density-temperature relation for the process gases.

Electron-Impact Cross Sections for Ionization and Excitation

Y.-K. Kim, K.K. Irikura, M.E. Rudd, M.A. Ali, and P.M. Stone
This is a database primarily of total ionization cross section of molecules by electron impact. The database also includes cross section for a small number of atoms and energy distributions of ejected electrons for H, He, and H2. The cross sections were calculated using the Binary-Encounter-Bethe (BEB) model, which combines the Mott cross section with the high-incident energy behavior of the Bethe cross section. Selected experimental data are included. Electron-impact excitation cross sections are also included for some selected atoms.

Potential Energy Surface Database of Group II Dimer Molecules

S. Kotochigova and P. Julienne
The purpose of this work is to provide critical atomic and molecular data needed in order to evaluate the feasibility of using laser cooled and trapped Group II atomic species (Mg, Ca, Sr, and Ba) for ultra-precise optical clocks or quantum information processing devices.

Atomic Weights and Isotopic Compositions

J. S. Coursey, D. J. Schwab, and R. A. Dragoset
This database contains the isotopic compositions or abundances of those elements which have characteristic terrestrial compositions. Atomic weights and relative atomic masses are also available for elements 1 through 112, 114 & 116.

*

stock photo render of molecule 5212864
© suravid/2010 Shutterstock.com

Contact

General Information:
301-975-4200 Telephone
301-975-3038 Facsimile

100 Bureau Drive, M/S 8400
Gaithersburg, MD 20899-8400