The one-electron density matrix (dm) of a number of crystalline systems—lithium, graphite, boron nitride, silicon, and beryllium—are considered here, as resulting from Hartree–Fock–scf-lcao calculations. The influence of structural and computational parameters is discussed. It is shown in particular why the structure of chemical bonds in semiconductors leads to an oscillating long-range behavior of the dm, similar to that observed in metals, where these oscillations are related to the very existence of a Fermi surface. Concerning computational parameters, the influence of the density of sampling k points and of basis set on the calculated dm is considered; it is shown that the choice of the basis set is not a very critical one as far as the dm range is concerned. Some critical aspects of the interrelation between dm range and exchange part of the Fock Hamiltonian are analyzed.
Density matrix of crystalline systems. II. The influence of structural and computational parameters
ORLANDO, Roberto
1990-01-01
Abstract
The one-electron density matrix (dm) of a number of crystalline systems—lithium, graphite, boron nitride, silicon, and beryllium—are considered here, as resulting from Hartree–Fock–scf-lcao calculations. The influence of structural and computational parameters is discussed. It is shown in particular why the structure of chemical bonds in semiconductors leads to an oscillating long-range behavior of the dm, similar to that observed in metals, where these oscillations are related to the very existence of a Fermi surface. Concerning computational parameters, the influence of the density of sampling k points and of basis set on the calculated dm is considered; it is shown that the choice of the basis set is not a very critical one as far as the dm range is concerned. Some critical aspects of the interrelation between dm range and exchange part of the Fock Hamiltonian are analyzed.
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
