There was a mistake in the input file (definition of the R1and H1) .So I made it correct and ran again.But the same error was obtained.I have no idea where it goes wrong since I am new to qm/mm.I saw some similar post where it says the SHAKE is causing this problem and as a solution, it was said to turn off the shake off (reduce the timestep). But in this script, I guess it is not possible.If anyone has used sccdftb method with QM/MM minimization can you please please guide me in order to correct this error?
Input file
*SCCDFTB
*
bomblev -2 !For parameters
! Topology file
! -------------
stream toppar.str
stream addlink.str
open read unit 18 card name "step1_sys_tcts_with_link_atoms.psf" !changing psf to cmp1
read psf unit 18 card
set RADIUS 40
set sys tcts_sccdftb ! system from labbook ??
open unit 15 read card name "step1_sys_tcts_with_link_atoms.crd"
read coor card unit 15
close unit 15
define QM sele (segid R1 .or. segid H1) show end !
define MM sele .not. QM end
!endif
! delete atoms sele resname TIP3 end
cons fix sele none end
!mini abnr nstep 100
open write form unit 13 name check.pdb
write coor pdb unit 13
close unit 13
scalar WMAIN set 1.0 sele (QM) .and. type P* SHOW end ! main coordinate weights
scalar WMAIN set 2.0 sele (QM) .and. type O* SHOW end
scalar WMAIN set 3.0 sele (QM) .and. type N* SHOW end
scalar WMAIN set 4.0 sele (QM) .and. type C* SHOW end
scalar WMAIN set 5.0 sele (QM) .and. type H* SHOW end
scalar WMAIN set 5.0 sele (QM) .and. type QQH1 SHOW end
!endif
! Do not forget about the link atom
update atom fshift noextend cdie vdw vfswitch eps 1.0 - ! constant dielectric and classical force shift method
cutnb 14 ctofnb 12 ctonnb 10.0 -
WMIN 1.5 inbfrq -1
!WE WILL NOW GO THROUGH A SERIES OF MINIMIZATIONS
define backbone sele segid RIC .and. (type C .or. type CA .or. type O .or. type N) end
define include sele .byres. (point 0.0 0.0 0.0 cut @RADIUS) end
!Keep outside fix ALL the time
cons fix sele .not. include end ! Everything outside is fixed
shake bonh tol 1.0e-10 param sele MM end
!NOW WE WILL WORK WITH INCLUDE
SCCDFTB REMOve SELE QM end - ! classical energies within QM atoms are removed
TEMP 0.00 SCFT 0.000001 EXGR - ! electronic temp (fermi) , convergence criteria
chrg -2.00 HBON D3RD mull ! MIXE 1 !slash NOC RC 50 BA 2 LT 5 !without dispersion
!#######################################################
!#################################################
energy
open read unit 4 formatted name wat45.pot
sbound read unit 4
close unit 4
sbound set xref 0.0 yref 0.0 zref 0.0 assign 1 -
sele (resname TIP3 .and. type OH2) end
!SETUP REACTION COORDINATES
!#########################################################
!reaction distance
!###################################################
cons fix sele none end
cons fix sele .not. include end
mini abnr nstep 100 tolegr 0.05
cons fix sele .not. include end
open write form unit 13 name "@SYS.crd"
write coord card unit 13
* Minimized QMMM
*
write coord pdb name "@SYS.pdb" sele all end
open write form unit 15 name "@SYS.psf"
write psf card unit 15
stop
the part of the output file where the error was obtained
CHARMM>
CHARMM> !#######################################################
CHARMM>
CHARMM> !#################################################
CHARMM> energy
NONBOND OPTION FLAGS:
ELEC VDW ATOMs CDIElec FSHIft VATOm VFSWIt
BYGRoup NOEXtnd NOEWald
CUTNB = 14.000 CTEXNB =999.000 CTONNB = 10.000 CTOFNB = 12.000
CGONNB = 0.000 CGOFNB = 10.000
WMIN = 1.500 WRNMXD = 0.500 E14FAC = 1.000 EPS = 1.000
NBXMOD = 5
There are 13220460 atom pairs and 70627 atom exclusions.
There are 0 group pairs and 8566 group exclusions.
Generating nonbond list with Exclusion mode = 5
== PRIMARY == SPACE FOR 17724330 ATOM PAIRS AND 0 GROUP PAIRS
General atom nonbond list generation found:
13192711 ATOM PAIRS WERE FOUND FOR ATOM LIST
783507 GROUP PAIRS REQUIRED ATOM SEARCHES
ewevge: ier = 155
***** LEVEL -5 WARNING FROM *****
***** SCCDFTB not converged.
******************************************
BOMLEV ( -1) IS REACHED - TERMINATING. WRNLEV IS 5
Last edited by vht; 08/10/20 03:41 PM.