ISSN:
0020-7608
Keywords:
Computational Chemistry and Molecular Modeling
;
Atomic, Molecular and Optical Physics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The theory of the potential energy curve of dimers Na2 and Be2 embedded in a cold dense plasma is first developed, starting from linear response theory plus a low-order gradient expansion. The results of this treatment are then reinterpreted, following the proposal of Perrot and March, in terms of bond midpoint properties. By comparison with full nonlocal density functional theory, the merits, and the limitations, of low-order gradient expansions are then assessed for Na2 and Be2 in dense plasmas. Use is made in this discussion of a pair potential extracted by inversion of the measured structure factor for liquid Na just above its freezing point. There is truly excellent agreement with the full density functional treatment of Perrot and March. The question is then addressed as to the relevance of the characterization by bond midpoint properties of the potential energy curve for dimers in a dense plasma to free space diatomic molecules and molecular ions. For H2+, it is demonstrated that such a characterization is exact. Heavier homonuclear diatoms are then considered, withi a low-order density gradient framework. It is emphasized that bond midpoint properties can again be used to characterize the potential energy curve. However, to obtain the electron density and its derivatives at the bond midpoint, it is now essential to solve the two-center problem in free space diatomics, whereas for Na2 and Be2 in sufficiently dense plasmas the superposition of one-center densities is an adequate starting point within the density functional framework.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/qua.560382460
