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Valence energies for crystalline C, Si, Ge, and Sn with diamond structurehave been determined using an ab-initio approach based on information fromcluster calculations. Correlation contributions, in particular, have beenevaluated in the coupled electron pair approximation (CEPA), by means ofincrements obtained for localized bond orbitals and for pairs and triples ofsuch bonds. Combining these results with corresponding Hartree-Fock (HF) data,we recover about 95 % of the experimental cohesive energies. Lattice constantsare overestimated at the HF level by about 1.5 %; correlation effects reducethese deviations to values which are within the error bounds of this method. Asimilar behavior is found for the bulk modulus: the HF values which aresignificantly too high are reduced by correlation effects to about 97 % of theexperimental values.Comment: 22 pages, latex, 2 figure

Electron correlations for ground-state properties of group-IV semiconductors