Calculated  Other theory  Expt.  
lattice constant (Ang)  (a) 5.35, (b) 5.39, (c) 5.41  5.40  5.43 
band gap (eV)  (a) 0.54, (b) 0.52, (c) 0.54  0.52  1.17 
Lattice constant (Exp.)  D. R. Lide, 1993 CRC Handbook of Chemistry and Physics 73rd edn (Boca Raton, FL: Chemical Rubber Company Press) 
Lattice constant (Theory)  S. Q. Wang and H. Q. Ye, J. Phys: Condens. Matter 15, L197 (2003) 
Band gap (Exp.)  Zahlenwerte und Funktionen aus Naturwissenschaften und Technik, LandoltBornstein, New Series (Springer Verlag, New York, 1982), Vol. III, Pt. 23a. 
Band gap (Theory)  W. Ku and A. G. Eguiluz, Phys. Rev. Lett. 89, 126401 (2002) 
Calculation conditions 

Version  OpenMX2.72 
Basis set  (a) Si5.5Rs2p2d1 
(b) Si6.0Rs2p2d1  
(c) Si6.5Rs2p2d1  
Pseudo potential  Si_LDA.vps as scalar relativistic VPS 
Functional  LDA 
spinorbit coupling  None 
Spin noncollinearity  None 
Ecut  130 Ryd 
kpoint  10 x 10 x 10 (for SCF), 15 x 15 x 15 (for DOS) 