Stability of a chemically bound helium compound in highpressure solid helium
Abstract
HHeF, a chemicallybound helium compound, has been predicted to be metastable in the gas phase. It decays by tunneling through energy barriers in picosecond timescales into He+HF and H+He+F. This paper studies the stability of HHeF in pressurized solid helium. Using realistic potentials for the HHeF/He interaction, the potential energy along the minimum energy paths for decomposition is evaluated, and tunneling decay times are computed by the WKB approximation. It is found that for pressures above 500 MPa, decomposition into H+He+F is completely suppressed. At 23 GPa, the highest pressure studied, the timescale for HHeF→He+HF is in the millisecond range. At pressures well above 23 GPa, HHeF is thus expected to remain stable indefinitely.
 Publication:

Journal of Chemical Physics
 Pub Date:
 September 2002
 DOI:
 10.1063/1.1506150
 Bibcode:
 2002JChPh.117.5105B
 Keywords:

 82.30.Lp;
 62.50.+p;
 82.20.Kh;
 Decomposition reactions;
 Highpressure and shock wave effects in solids and liquids;
 Potential energy surfaces for chemical reactions