Abstract
High-level quantum-chemical calculations, using the coupled-cluster approach and extended one-particle basis sets, have been performed for (( clusters embedded in a Madelung potential. The results of these calculations are used for setting up an incremental expansion for the correlation energy of bulk MgO. This way approximately 96% of the experimental cohesive energy of the MgO crystal is recovered. It is shown that only about 60% of the correlation contribution to the cohesive energy is of intraionic origin, the remaining part being caused by van der Waals–like interionic excitations.
- Received 2 February 1995
DOI:https://doi.org/10.1103/PhysRevB.52.4842
©1995 American Physical Society