Dear Tao Junguang, > order to figure out the reason, I run another one setting > calculation='relax' with the other parameters the same, and I got the > value of 1.64eV, which sounds quite reasonable for DFT. So I am wonder > is any chance that the 'nscf' and 'relax' different so much ?
Sure they differ! calculation='relax' request an structural relaxation (i.e. the internal coordinates are optimized). Do your initial and final coordinates differ significantly? In that case, the reason for the differences in the electronic gaps is quite evident. Best regards, Felipe -- Felipe Valencia Hernandez Dipartimento di Fisica G. Galilei Via Marzolo 8 I-35131 Padova, Italy ********* ***** ** *************************.* ****** *********** ** *******o ******* ********* **** ****`- ******* ********* ***** ****** ********** **** ## ***** ***** ## **** ### ***** ### **** #,,, ***,,, ##,,, **,,,
