Open AccessContributions of fourbody interactions to compressibility of solid helium
Author(s) -
Chunling Tian,
Fusheng Liu,
Ling-Cang Cai,
Fuqian Jing
Publication year - 2003
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.52.1218
Subject(s) - helium , compressibility , many body theory , physics , ab initio , range (aeronautics) , helium 4 , binding energy , equation of state , atomic physics , thermodynamics , materials science , condensed matter physics , quantum mechanics , composite material
Based on a mangbody expansion of shortrange interatomic force,the fourbody interactions in compressed solid helium are computed by ab initio HartreeFock selfconsistent field technique and the atomic cluster method. It is concluded that fourbody terms give a repulsive contribution to the binding energy. By combination of the present manybody expansions with Aziz's longrange attractive potential, the equation of state(EOS) (T=0K) is calculated and compared with available experimental data. Results emphasize the importance of the fourbody interactions in compressed solid He. If only twobody interactions are included such as in the description of the helium gas, the pressure is much overestimated. Good agreement with experiments can only be extended up to about 10 GPa when the threebody corrections are added to; however, the predicted compression curve is obviously lower than that obtained in recent experiments at above 10 GPa. Our study shows that fourbody corrections can bring the calculated EOS into a good agreement with experimental data at pressures of 10\_27GPa. Our result also implies that the higherorder manybody effects should be taken into account at higher pressures.