Update: CHARMM now supports many open files, whatever the OS will allow; start from UNIT 101 and increment upwards.

You have to use the MERGE command (dynamc.doc) to combine files; I often do a temporary merge from the storage location to the /scratch volume of a machine, then run a series of analysis on files that have been merged to 1 ns chunks. Since this is the Script Archive, here's the script; the @J variable must be passed from the command line--

* merge 10:1
*

bomblev -1

! READ RTF, PARAM FILES
stream rtfprm.str
! READ PSF, COOR
stream psfcrd.str
! AND SETUP CRYSTAL (IMPORTANT!!!)
stream cryst.str

! COMPUTE LAST OF SET
calc ilst @J + 9
! START FROM UNIT 21
set iu 21
! INPUT FILE OPEN LOOP
label flp
open unit @IU read file name dyn@J.trj
incr iu by 1
incr j by 1
if j .le. @ILST goto flp

! OPEN THE OUTPUT FILE AS UNIT 19
open unit 19 write file name /scratch/dyn@K.trj
! MERGE THE FILES TO CREATE A NEW ONE
merge coor firstu 21 nunit 10 output 19 nfile 1000

stop

Last edited by rmv; 07/28/14 10:34 PM. Reason: no. of files update

Rick Venable
computational chemist