Dear Zhu Xi, I have not run your input file, but assuming that it is correct and this 0.625eV is what you read directly from the output, this Fermi energy should also be correct. If you are interested in the work function of the (3,3)CNT you will have to obtain the difference between a vacuum potential and the Fermi energy. In short the potential in the vacuum != 0 due to the use of periodic boundary conditions. If you use pp.x to obtain the potential remember that is is output in Rydbergs. This is all discussed other times on the forum.
best of luck, Nicholas On Thu, 10 Jan 2008, Zhu Xi wrote: > Dear users, > > I run a scf calculation of (3,3)CNT, but the fermi energy is 0.652eV, can > anyone give some suggestion? thanks > > ==================================================================================== > > &control > calculation='scf', > PSEUDO_DIR='./', > prefix='33', > forc_conv_thr=1.0D-4, > / > &SYSTEM > ibrav = 0, > celldm(1)= 18.8972612499, > nat = 12, > ntyp = 1, > ecutwfc = 40.0 , > nosym = .true. , > nbnd = 48 , > occupations= 'smearing',degauss = 0.001 > > / > &electrons > conv_thr = 1.D-6, > mixing_beta = 0.5D0, > / > CELL_PARAMETERS > 1.0 0.000000000 0.000000000 > 0.000000000 1.0 0.000000000 > 0.000000000 0.000000000 0.245951 > ATOMIC_SPECIES > C 12.00000 C.pz-vbc.UPF > ATOMIC_POSITIONS (crystal) > C 0.625289967 0.669611155 0.250000000 > C 0.487077242 0.709466388 0.250000000 > C 0.291384631 0.523168925 0.250000000 > C 0.374710033 0.330388845 0.750000000 > C 0.512922758 0.290533612 0.750000000 > C 0.708615369 0.476831075 0.750000000 > C 0.416429985 0.692001578 0.750000000 > C 0.675464001 0.616817067 0.750000000 > C 0.312292454 0.592869751 0.750000000 > C 0.583570015 0.307998422 0.250000000 > C 0.324535999 0.383182933 0.250000000 > C 0.687707546 0.407130249 0.250000000 > K_POINTS automatic > 1 1 11 0 0 0 > > ================================================== > ***************************************** Nicholas E. Singh-Miller Ph.D. Candidate Prof. Marzari Group (quasiamore.mit.edu) Materials Science and Engineering Massachusetts Institute of Technology 13-4066 (617)324-0372 *****************************************
