The distance between some ions is very small

Message

mcosta · #1 Post by **mcosta** » Thu Nov 13, 2008 10:20 pm

I'm trieing to run a supercell with 72 atoms but the program keeps saying:

| The distance between some ions is very small |
| please check the nearest neigbor list in the OUTCAR file |
| I HOPE YOU KNOW, WHAT YOU ARE DOING |
| |
-----------------------------------------------------------------------------

Here is my POSCAR file:

silicon
5.52
2.44948006 1.41420996 0.00000000
0.00000000 2.12129998 0.00000000
0.00000000 0.00000000 1.73204994
72
Angstrom
-0.80323350 -0.00490960 2.30527282
-0.19105580 0.34993297 2.30408645
-0.80385184 0.70196289 2.30476546
-0.19128025 1.05683196 2.30459642
-0.80423331 1.40889311 2.30561090
-0.19198133 1.76346409 2.30500197
-1.21153855 -0.00359493 2.16071320
-0.59930110 0.34863007 2.16013002
-1.21236753 0.70340979 2.16060543
-0.59965634 1.05568564 2.16082931
-1.21229148 1.41012180 2.16042614
-0.60009438 1.76236522 2.16077852
-2.02863312 -0.00247899 2.30451989
-1.41645491 0.34985381 2.30511808
-2.02912498 0.70418459 2.30450511
-1.41702902 1.05691636 2.30500293
-2.02835178 -0.70929891 2.30439425
-1.41582346 -0.35717174 2.30506182
-2.43683648 -0.00358388 2.16034555
-1.82460999 0.35094184 2.16011477
-2.43730807 0.70308805 2.16048813
-1.82518113 1.05791068 2.15995765
-2.43645692 -0.71040326 2.15984488
-1.82402980 -0.35568750 2.16011286
-1.21163154 -0.00354873 1.72748554
-0.59918004 0.34922734 1.72709334
-1.21280575 0.70309621 1.72750914
-0.60001522 1.05530274 1.72776949
-1.21240032 1.41036355 1.72728157
-0.59962142 1.76311040 1.72773027
-1.00763392 0.35002446 1.58313310
-0.39563063 -0.00443152 1.58294904
-0.39534366 0.70271921 1.58221734
-1.00837779 1.05645800 1.58341765
-0.39622572 1.40917850 1.58365393
-1.00780964 -0.35744819 1.58332980
-2.43741035 -0.00273587 1.72748840
-1.82525301 0.35086232 1.72716653
-2.43722892 0.70469838 1.72758651
-1.82531178 1.05825984 1.72694695
-2.43684578 -0.70927954 1.72683990
-1.82448971 -0.35562882 1.72706294
-2.23372149 0.35114112 1.58323789
-1.62013280 -0.00219909 1.58300126
-1.62127912 0.70452136 1.58316314
-2.23348546 -1.06290853 1.58245027
-1.62085915 -0.70955306 1.58298516
-2.23284745 -0.35545054 1.58273876
-2.23484755 0.35108513 1.15030074
-1.62154078 -0.00309420 1.15010226
-1.62252963 0.70454800 1.15031683
-2.23399806 -1.06292903 1.14950931
-1.62222111 -0.70958710 1.15013063
-2.23379350 -0.35505325 1.14984477
-2.02972078 -0.00157264 1.00544000
-1.41826010 0.35088244 1.00614023
-2.03059959 0.70454127 1.00546908
-1.41814590 1.05793774 1.00611055
-2.03039670 -0.70886612 1.00544262
-1.41684210 -0.35662609 1.00615108
-1.00975633 0.34944874 1.15022969
-0.39599875 -0.00411848 1.15004671
-0.39647049 0.70284057 1.14927244
-1.00973487 1.05578756 1.15047884
-0.39751828 1.40911198 1.15069950
-1.00849438 -0.35722628 1.15050411
-0.80436432 -0.00363478 1.00625944
-0.19232029 0.34955090 1.00491011
-0.80510527 0.70252413 1.00568867
-0.19239619 1.05675781 1.00546908
-0.80576813 1.40953171 1.00665057
-0.19353406 1.76278591 1.00596750

When I look at it with VMD it seems fine.

Any help??

Thanks

forsdan · #2 Post by **forsdan** » Sun Nov 16, 2008 10:03 pm

"Angstrom" is not a recognized keyword. You should either use "Cartesian" or "Direct". Please consult the manual.

http://cms.mpi.univie.ac.at/vasp/vasp/node63.html

Cheers
/Dan

wujian · #3 Post by **wujian** » Wed Jul 08, 2009 12:29 pm

sometimes，i use the "Direct" or the "Cartesian",but the question appear alao.i want to know why?thanks

forsdan · #4 Post by **forsdan** » Wed Jul 08, 2009 1:10 pm

The warning occurs when the distance between two atoms is shorter than the smallest RWIGS value multiplied by 1.2. So if you physically can't have that small distances between two atoms in your system, you have entered the coordinates incorrectly and will need to recheck your entries. Please consult the manual as well to make sure that you enter it properly.

Best regards,
/Dan Fors

<span class='smallblacktext'>[ Edited Wed Jul 08 2009, 03:45PM ]</span>