<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman,new york,times,serif;font-size:12pt">Dear All<br>I want to fix the distance between two atom during relaxation , the distance is 1.98 , but the code crash and the error is <br> target = 3.67419827<br> dmax = 2.79062000<br><br> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br> from init_constraint : error # 1<br> the target for constraint 1 is larger than the largest possible value<br> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br><br>why does it happen and what can I do?<br><br><br>this is my input
file:<br><br> &CONTROL<br> title = 'routile lattice BFGS' ,<br> calculation = 'relax' ,<br> restart_mode = 'from_scratch' ,<br> outdir = '/ptmp/kazempou/scratch' ,<br> pseudo_dir = './' ,<br> prefix = 'routil lattice default'
,<br> etot_conv_thr = 0.000000735 ,<br> forc_conv_thr = 0.0011668141375 ,<br> /<br> &SYSTEM<br> ibrav = 6,<br> celldm(1) = 8.68,<br> celldm(3) = 0.643,<br> nat =
6,<br> ntyp = 2,<br> ecutwfc = 15 ,<br> ecutrho = 400 ,<br> /<br> &ELECTRONS<br> conv_thr = 1.0D-4 ,<br> /<br> &IONS<br> /<br>ATOMIC_SPECIES<br> Ti 47.86700 ti.optgga2.fhi.UPF <br> O 15.99940 o.optgga1.fhi.UPF <br>ATOMIC_POSITIONS crystal <br> Ti 0.000000000 0.000000000
0.000000000 <br> Ti 0.500000000 0.500000000 0.500000000 <br> O 0.305300000 0.305300000 0.000000000 <br> O -0.305300000 -0.305300000 0.000000000 <br> O 0.805300000 0.194700000 0.500000000 <br> O 0.194700000 0.805300000 0.500000000 <br>K_POINTS automatic <br> 8 8 10 0 0 0 <br>CONSTRAINTS<br> 1 1.98 <br> 'distance' 2 4 <br><br>thanks a lot<br><br><div> </div>Ali
Kazempour<br><br><br><br><div><br>Fritz-Haber-Institut fax : ++49-30-8413 4701<br>der Max-Planck-Gesellschaft<br>Faradayweg 4-6 e-mail: kazempou@fhi-berlin.mpg.de<br>D-14 195 Berlin-Dahlem / German<div><br></div></div>
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