575 research outputs found
Metallic bonding due to correlations: A quantum chemical ab-initio calculation of the cohesive energy of mercury
Solid mercury in the rhombohedral structure is unbound within the
self-consistent field (Hartree-Fock) approximation. The metallic binding is
entirely due to electronic correlations. We determine the cohesive energy of
solid mercury within an ab-initio many-body expansion for the correlation part.
Electronic correlations in the shell contribute about half to the cohesive
energy. Relativistic effects are found to be very important. Very good
agreement with the experimental value is obtained.Comment: 4 pages, 1 figur
Discrete behavior of Seshadri constants on surfaces
Working over C, we show that, apart possibly from a unique limit point, the
possible values of multi-point Seshadri constant for general points on smooth
projective surfaces form a discrete set. In addition to its theoretical
interest, this result is of practical value, which we demonstrate by giving
significantly improved explicit lower bounds for Seshadri constants on P^2 and
new results about ample divisors on blow ups of P^2 at general points.Comment: 14 pages, to appear in J. Pure App. Algebr
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