Dear all, I used to calculate the structure and the energy of Pt dimers (two Pt atoms) in a large supercell. I have tested various structure in triplet, which is most stable state for single Pt atom. But the code report errors after a few bfgs steps like this: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% task # 0 from bfgs : error # 1 bfgs history already reset at previous step %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% I wondering how to deal with this situation.
my input files is shown as follows, &CONTROL calculation = 'relax' , restart_mode = 'from_scratch' , outdir = '/tmp/' , wfcdir = '/tmp/' , pseudo_dir = '/home/vega/espresso/pseudo/' , disk_io = 'none' , nstep = 1000 , / &SYSTEM ibrav = 8, celldm(1) =24.8624, celldm(2) = 0.8520, celldm(3) = 1.6964, nat = 2, ntyp = 1, nosym = .true. , ecutwfc = 30, ecutrho = 300, occupations = 'smearing', degauss = 0.007, nspin = 2, multiplicity = 3, / &ELECTRONS mixing_mode ='local-TF', mixing_beta = 0.4, / &IONS ion_dynamics = 'bfgs' , / ATOMIC_SPECIES Pt 195.08 Pt.pw91-n-van.UPF ATOMIC_POSITIONS crystal Pt 0.540794031 0.322983976 0.495002098 Pt 0.500777594 0.548429786 0.493029885 K_POINTS gamma the input parameters might not very suitable for the calculation of Pt dimers itself. But the parameters should be consistent with the previous calculation, which is composed of two Pt atoms on certain surface slab model. So could any one give me some suggestions? Thank you for reading vega -- ================================================================================== Vega Lew ( weijia liu) Graduate student State Key Laboratory of Materials-oriented Chemical Engineering College of Chemistry and Chemical Engineering Nanjing University of Technology, 210009, Nanjing, Jiangsu, China ****************************************************************************************************************** Email: vegalew at gmail.com Office: Room A705, Technical Innovation Building, Xinmofan Road 5#, Nanjing, Jiangsu, China ****************************************************************************************************************** -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100106/44473d7c/attachment.htm