Local-density-derived semiempirical nonlocal pseudopotentials for InP with applications to large quantum dots

摘要: In the same way that atomic calculations have been used previously to extract bare ionic pseudopotentials, self-consistent bulk can be construct screened pseudopotentials. We use such a method nonlocal pseudopotentials for InP. A series of bulk, local-density-approximation (LDA) are performed on few InP crystal structures, covering range unit-cell volumes, produce potentials {${\mathrm{V}}_{\mathrm{LDA}}$ (G)}. By solving set linear equations, we from these crystalline corresponding 'spherical LDA' (SLDA) ${\mathrm{v}}_{\mathrm{SLDA}}^{\mathrm{\ensuremath{\alpha}}g}$(|q|) sites \ensuremath{\alpha}=In or P. combination with part usual LDA SLDA give band structures and wave functions virtually indistinguishable results next step, apply changes local (while keeping at their values), fit experiment. Interestingly, this removal eigenvalue errors requires only small subtle in potential---mostly an upshift region near cation core, nearly no change bond center. Furthermore, result mostly conduction bands little effect valence bands. Because potential suffice experimental results, remain unchanged relative those original calculation. Hence, obtain semiempirical which ab initio LDA-quality experimentally measured effective masses, deformation potentials. The obtained here were deposited FTP site by interested readers. Since resulting 'soft' (with high-momentum components), they applied within plane-wave basis Gaussian correction large systems prohibitively expensive. As illustration, our calculate quantum size effects gaps dots sizes up 700 atoms. Good agreement is found between theoretical gaps. Fitting calculated ${\mathrm{E}}_{\mathrm{g}}$ (in unit eV) versus dot D \AA{}) gives =1.45+37.295/${\mathrm{D}}^{1.16}$ . This prediction differs significantly quadratic dependence ${\mathrm{D}}^{\mathrm{\ensuremath{-}}2.0}$ expected simple effective-mass theory.