Correcting overbinding in local-density-approximation calculations
نویسندگان
چکیده
We introduce a semiempirical method to correct the systematic equilibrium lattice parameters underestimation present in first principles calculations based on the local density approximation. The method consists in performing calculations under a negative pressure such that the calculated equilibrium volume matches the experimentally observed one. We find that elastic properties obtained under these conditions are typically in better agreement with experiment. We also observe that the negative pressure which needs to be applied to crystalline compound can be reliably interpolated by taking the concentration-weighted average of the pressures determined from pure crystals made of each of the elements present in the compound. In a large class of materials, the knowledge of one pressure per element is thus sufficient to correct most of the bias in lattice constants and elastic properties. We finally propose a simple model of the nonlocal contribution to the exchange-correlations energy that is able to explain the observed linear dependence between the required negative pressure and concentration. @S0163-1829~99!01324-7#
منابع مشابه
Non-local screened-exchange calculations for defects in semiconductors: vacancy in silicon
The microscopic structure of a silicon vacancy is studied theoretically using first-principles supercell calculations. Both the standard Kohn–Sham local-density approximation (LDA) scheme and the generalized Kohn–Sham screened-exchange local-density approximation (sX-LDA) scheme are used. The latter approximation is expected to improve the description of electronic levels in the gap region subs...
متن کاملDensity-functional calculations for III-V nitrides using the local-density approximation and the generalized gradient approximation
We have performed density-functional calculations for III-V nitrides using the pseudopotential plane-wave method where the d states of the Ga and In atoms are included as valence states. Results obtained using both the local-density approximation ~LDA! and the generalized gradient approximation ~GGA! for the exchangecorrelation functional are compared. Bulk properties, including lattice constan...
متن کاملTowards an Optimal Gradient-dependent Energy Functional of the PZ-SIC Form
Results of Perdew–Zunger self-interaction corrected (PZ-SIC) density functional theory calculations of the atomization energy of 35 molecules are compared to those of high-level quantum chemistry calculations. While the PBE functional, which is commonly used in calculations of condensed matter, is known to predict on average too high atomization energy (overbinding of the molecules), the applic...
متن کاملFirst-principles study on the electronic structure of Thiophenbithiol (TBT) on Au(100) surface
First principle calculations were performed using Density functional theory within the local spin density approximation (LSDA) to understand the electronic properties of Au(100)+TBT system and compare the results with Au(100) and bulk Au properties. Band structure, the total DOS and charge density for these materials are calculated. We found that the HOMO for Au(100)+TBT becomes broader than Au...
متن کاملFirst-principles study on the electronic structure of Thiophenbithiol (TBT) on Au(100) surface
First principle calculations were performed using Density functional theory within the local spin density approximation (LSDA) to understand the electronic properties of Au(100)+TBT system and compare the results with Au(100) and bulk Au properties. Band structure, the total DOS and charge density for these materials are calculated. We found that the HOMO for Au(100)+TBT becomes broader than Au...
متن کامل