van der Waals interaction of the hydrogen molecule: An exact implicit energy density functional
Abstract
We verify that the van der Waals interaction and hence all dispersion interactions for the hydrogen molecule are exactly soluble. The constants A=6.499 026 7..., B=124.399 083 5..., and C=1135.214 039 8... (in Hartree units), first obtained approximately by Pauling and Beach using a linear variational method, can be shown to be obtainable to any desired accuracy via our exact solution. In addition, we shall show that an implicit energy density functional can be obtained, whose variational solution rederives the exact solution for this problem. Thus we present an exact and practical static density functional for this system. We conclude with remarks about generalizing the method to other hydrogenic systems and also to helium.
 Publication:

Physical Review A
 Pub Date:
 July 2000
 DOI:
 10.1103/PhysRevA.62.012506
 arXiv:
 arXiv:quantph/9911096
 Bibcode:
 2000PhRvA..62a2506C
 Keywords:

 31.15.Ew;
 34.30.+h;
 Densityfunctional theory;
 Intramolecular energy transfer;
 intramolecular dynamics;
 dynamics of van der Waals molecules;
 Quantum Physics;
 Condensed Matter  Strongly Correlated Electrons;
 Physics  Atomic and Molecular Clusters;
 Physics  Chemical Physics
 EPrint:
 11 pages, 13 figures and 28 references