Dear PW_Forum Thanks to Guido... this is help me. now I try again input and it is work.
Thanks again Success for your research Sincerely Yours. Rahmat Gunawan PostGraduate Student Dept. of Chemistry Institut Teknologi Bandung West Java, Indonesia >> ATOMIC_POSITIONS crystal >> H 0.000000000 0.000000000 3.250000000 >> C 0.000000000 0.000000000 0.000000000 >> C 0.333333333 0.666666666 0.000000000 >> C 0.000000000 0.000000000 0.500000000 > > You have an odd number N of electrons per unit cell, so your system IS > metallic, and one cannot simply occupy the lowest N/2 bands as would be > the default for an insulator. > Hence you have to specify how to fill the electron bands. > See file Doc/INPUT_PW, variables "occupation", "degauss", "smearing" and > references given there for details. > > [If you want to think more about that, consider an H atom in a large box, > suitable for an isolated-atom calculation. Then you have 1 electron per > unit cell, which is odd again, so the system made of the repeated H > atoms far away the one from the other is metallic, and you will find > with PWscf that the lowest energy is given by half-filling a band which > is nothing more than the (bonding) combination of the 1s orbitals, as it > should be. Moreover, the results will not be much affected by the values > you choose for the variables specified above. Can you imagine why?] > > Hope this helps, > Guido > > Guido Fratesi > Dipartimento di Fisica > Universita` degli studi di Milano > Via Celoria, 16 - 20133 MI (Italy) > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum >
