Do you have a CIF or any other structure file for Au? Also if Au does not have degenerate symmetries, just providing 2-atom primitive cell should work too.
Prat On Thu, Apr 14, 2011 at 2:34 PM, janakiraman balachandran <[email protected] > wrote: > 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 >>>> >>> >>> >> >
