Dear Dangxin Thank you for the reply. Why do you say that i need to give only one atom? How would the program know the difference between FCC and BCC if i give only one atom?
I would prefer to do a bulk calculation with 14 atom FCC since i need that output somewhere else. On Thu, Apr 14, 2011 at 5:29 PM, Dangxin Wu <[email protected]> wrote: > Are you doing a bulk calculation? There should be only one atom in one unit > cell of FCC according to your input cell parameters (at [0, 0, 0]). Looking > at the warnings in your output, many of the atoms are repeated (they are > exactly the same atom). > > Dangxin > > ------------------------------ > *From:* janakiraman balachandran <[email protected]> > > *To:* [email protected] > *Cc:* Prathibha Ramaprasad <[email protected]> > *Sent:* Thu, April 14, 2011 3:19:39 PM > *Subject:* Re: [SIESTA-L] Au unit cell not converging > > Hi > Thanks for the reply. I use one unit cell of FCC. It has 14 Au atoms. > Infact i visualized them using molden and computed the distance. I dont see > anything wrong with the input > > Ram > > On Thu, Apr 14, 2011 at 5:07 PM, Prathibha Ramaprasad <[email protected]>wrote: > >> Ram, >> >> Most likely you have included more atoms than there should be in the unit >> cell, for example the ones belonging to an adjacent unit cell (as most >> crystal viewing tools do). Carefully examine the atoms at the border of your >> unit cell and remove the extra ones. As siesta uses periodic cells, these >> atoms overlap and give you the error you have mentioned. >> >> Prat >> >> >> On Thu, Apr 14, 2011 at 1:51 PM, janakiraman balachandran < >> [email protected]> wrote: >> >>> Hi >>> I'm trying to run a Au unit cell in siesta. However i'm getting a warning >>> stating the atoms on opposite surfaces are too close (distance 0). >>> Subsequently i get an error that says the leading minor is not positive >>> definite and hence diagonalization cannot be performed. I'm very sure that i >>> have used the correct Lattice distance. I'm not sure what causes the >>> problem. I have attached the fdf file. I have commented the * >>> kgrid_Monkhorst_Pack* and* BandLines*. But even with them uncommented, i >>> get the same error >>> >>> I need to make it work as soon as possible. Hence any help to sort this >>> problem would be greatly appreciated >>> >>> Thank you >>> >>> Regards >>> Ram >>> >> >> >
