UHF Method Research Articles

Ab initio UHF calculations. Part 4.—The radical ion NH+3

The hyperfine coupling constants for NH+3 are calculated to be aN= 10.57, aH=–22.65 G using the ab initio UHF method after spin annihilation of the quartet spin state and optimization of the NH bond length and hydrogen atom orbital exponent. It is calculated that the effect of the out-of-plane zero-point energy vibration modifies the hyperfine coupling constants to aN= 16.92, aH=–20.02 G.

The cyanide radical

The hyperfine coupling constants for the CN radical have been calculated using the ab initio UHF method with spin annihilation in the LCGO MO approximation scheme ( a N = −6.182 Gauss; a C = 339.2 Gauss). The results are interpreted to suggest that the unpaired electron is in a non-bonding sp hybrid orbital on the carbon atom.

Measurement of moisture in asbestos cement at ultrahigh frequencies

1. The application of the UHF method based on the relationship between the wave power attenuation and moisture in asbestos cement has several advantages in evaluating moisture content as compared with other materials.