Re: [SIESTA-L] -ve frequency in phonon calculation

2006-06-05 Thread Andrei Postnikov
On Mon, 5 Jun 2006, bipul rakshit wrote: | hi siesta users, | i am calculating the phonon frequencies of MgB2. i got nice match in bulk modulus of 156 GPa with LDA. While the experimental value is 151 GPa. | | With that Pseudopotential when i tried to calculate the phonon frequency by Vi

[SIESTA-L] -ve frequency in phonon calculation

2006-06-05 Thread bipul rakshit
hi siesta users, i am calculating the phonon frequencies of MgB2. i got nice match in bulk modulus of 156 GPa with LDA. While the experimental value is 151 GPa. With that Pseudopotential when i tried to calculate the phonon frequency by Vibra. i got -ve frequencies. can any body