Since your system is simple cubic, and your first and second atoms position are (0,0,0) and (-1,0,0), which are both at the vertex position of a cubic, thus the 1st and 2nd atoms at exactly same position (please think about the translation in crystal). Actually, in you input file, atom 1~4 aimed the same position.
-- GAO Zhe CMC Lab, Materials Science & Engineering Department, Seoul National University, South Korea At 2012-03-27 06:33:35,"mohamed makhyoun" <makhyoun2 at yahoo.com> wrote: | Dear All: By running the given input file for pw.x I get the error: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% from check_atoms : error # 1 atoms # 1 and # 2 overlap! %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Although I checked the input by XCRYSDEN visualization program and nothing is wrong. I appreciate any help. Best Regard Mohamed ################################################################### &CONTROL calculation = 'scf' , prefix='cu3nbs4' restart_mode = 'from_scratch' , outdir = '$TMP_DIR/' , pseudo_dir = '/home/mohamed/espresso/exec/pseudo' , verbosity = 'default' , / &SYSTEM ibrav=1 celldm(1)= 10.397 , nat = 20, ntyp = 3, ecutwfc = 60. , nbnd=90, / &ELECTRONS conv_thr=1.0D-8 , / ATOMIC_SPECIES Nb 92.9064 Nb.pbe-sR-sc-us.UPF Cu 63.546 Cu.pbe-sR-us.UPF S 32.06 S.pbe-van-bm.UPF ATOMIC_POSITIONS crystal Nb 0.000000000 0.000000000 0.000000000 Nb -1.000000000 0.000000000 0.000000000 Nb 0.000000000 0.000000000 -1.000000000 Nb 1.000000000 0.000000000 0.000000000 Cu 0.500000000 0.000000000 0.000000000 Cu 0.000000000 0.000000000 -0.500000000 Cu -0.500000000 0.000000000 0.000000000 Cu 0.000000000 -0.500000000 0.000000000 Cu 0.000000000 0.500000000 0.000000000 Cu 0.000000000 0.000000000 0.500000000 S 0.242599953 0.242599953 0.242599953 S 0.242599953 -0.242599953 -0.242599953 S -0.242599953 0.242599953 -0.242599953 S -0.242599953 -0.242599953 0.242599953 S -0.757400047 0.242599953 0.242599953 S 0.242599953 0.242599953 -0.757400047 S -0.757400047 -0.242599953 -0.242599953 S 0.757400047 0.242599953 -0.242599953 S -0.242599953 -0.242599953 -0.757400047 S 0.757400047 -0.242599953 0.242599953 K_POINTS gamma | -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120327/e0400c5c/attachment.htm