<div>Dear Eyvaz,</div>
<div>Thank you.</div>
<div>I checked the strcuture again using XCRYSDEN, </div>
<div>and found no problems related to the lattices.</div>
<div> </div>
<div>Regards,</div>
<div> </div>
<div>Hai-Ping</div>
<div><br><br> </div>
<div><span class="gmail_quote">On 8/20/06, <b class="gmail_sendername">Eyvaz Isaev</b> <<a href="mailto:eyvaz_isaev@yahoo.com">eyvaz_isaev@yahoo.com</a>> wrote:</span>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">Hi,<br><br>It seems your lattice choice is not correct. Please<br>have a look at<br><a href="http://cst-www.nrl.navy.mil/lattice/struk/c5.html">
http://cst-www.nrl.navy.mil/lattice/struk/c5.html</a><br><br>Bests,<br>Eyvaz.<br><br>--- lan haiping <<a href="mailto:lanhaiping@gmail.com">lanhaiping@gmail.com</a>> wrote:<br><br>> Dear All,<br>> I also have calculated gamma phonon frequencies of
<br>> anatase TiO2 .<br>> I run ph.x caculation after relaxing the structure,<br>> but 9 of 18 frequencies<br>> are minus.<br>><br>> Would you please give me some hints and help?<br>><br>> input settings are below, thank you in advance !
<br>><br>> *phonons of TiO2 at Gamma<br>> &inputph<br>> tr2_ph=1.0d-14,<br>> recover=.true.,<br>> epsil=.true.,<br>> prefix='tio2',<br>> fildyn='TiO2-gamma.dyn',<br>> outdir='/home/haiping/tmp/'
<br>> /<br>> 0.0 0.0 0.0*<br>> **<br>> *Relaxing calculation input :*<br>> *&CONTROL<br>> title = 'TiO2' ,<br>> calculation = 'relax',<br>> verbosity = 'default',<br>
> tprnfor = .true.,<br>> outdir = '/home/haiping/tmp/',<br>> prefix = 'tio2',<br>> disk_io = 'default',<br>> nstep = 200,<br>> pseudo_dir =
<br>> '/home/haiping/espresso/pseudo/',<br>> /<br>> &SYSTEM<br>> ibrav= 14,<br>><br>> celldm(1)=10.2856,celldm(2)=1.0,celldm(3)=1.0,<br>><br>> celldm(4)=-0.759357,celldm(5)=-0.759357
,<br>> celldm(6)=0.518714<br>> nat = 6 ,<br>> ntyp = 2 ,<br>> nbnd = 30 ,<br>> ecutwfc = 30.0000000000,<br>> ecutrho = 160.000
,<br>> occupations = 'fixed' ,<br>> /<br>><br>><br>> &ELECTRONS<br>> electron_maxstep = 100,<br>> conv_thr = 1.0e-07,<br>> mixing_mode = 'plain' ,<br>> startingpot = 'atomic' ,
<br>> startingwfc = 'atomic' ,<br>> mixing_beta = 0.300000000,<br>> mixing_ndim = 8,<br>> diagonalization = 'david_overlap' ,<br>> diago_david_ndim = 8,<br>> /<br>><br>> &IONS
<br>> ion_dynamics = 'bfgs',<br>> pot_extrapolation = 'first_order',<br>> wfc_extrapolation = 'first_order',<br>><br>> /<br>><br>> ATOMIC_SPECIES<br>> O 15.999
O.pw91-van_ak.UPF<br>> Ti 47.867 Ti.pw91-nsp-van.UPF<br>> ATOMIC_POSITIONS crystal<br>> Ti 0.00000 0.00000 0.00000<br>> Ti 0.75000 0.25000 0.50000<br>> O 0.20800 0.20800 -0.00000<br>> O
0.95800 0.45800 0.50000<br>> O 0.54200 0.04200 0.50000<br>> O 0.79200 0.79200 -0.00000<br>> K_POINTS automatic<br>> 6 6 7 0 0 0<br>><br>> *<br>><br>><br>> On 8/19/06, Ezad Shojaee <
<a href="mailto:ezadshojaee@hotmail.com">ezadshojaee@hotmail.com</a>><br>> wrote:<br>> ><br>> > hi<br>> > i am trying to calculate phonon frequencies at<br>> gamma point of<br>> > TiO2(anatase)
<br>> > and i have relaxed the structure enough (i think<br>> )but performing PH.Xafter<br>> > scf, 2of 18 frequencies are minus!<br>> > i want to know that what technical problem do i<br>> have? does anyone
<br>> > calculate<br>> > these beore?<br>> > any suggestion will be appreciated<br>> ><br>> ><br>><br>_________________________________________________________________<br>> > Express yourself instantly with MSN Messenger!
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