Hello
I would like to ask a few questions about modelling the Montmorillonite.
I built a model of Na+MMT using those two papers
S. I. Tsipursky, V. A. Drits, Clay Minerals 19 (1984) 177-193.
R. Toth, A. Coslanich, M. Ferrone, M. Fermeglia, S. Pricl, S. Miertus, E. Chiellini, Polymer 45 (2004) 8075-8083.
With the model built, It was time to optimize the cell, I tried the ClayFF force field version for Discover provided in this discussion forum, but I end up with the following error message:
INPUT FILES
___________
File Type Name
--------- ----
Forcefield C:\PROGRA~1\Accelrys\MATERI~2.0\share\Discover\res/clayff.frc
Molecular data MMT.mdf
Coordinate MMT.car
Space Group (C2/M)
Periodic Boundary Conditions
____________________________
Length (A) Angle (degrees)
---------- ---------------
a 5.20000 alpha 90.00000
b 9.20000 beta 99.00000
c 10.13000 gamma 90.00000
Error: Energy expression: cannot find parameters for bond: O2(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O3(ob)-Al(ao)
Error: Energy expression: cannot find parameters for bond: O3(ob)-Al(ao)
Error: Energy expression: cannot find parameters for bond: O3(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: Si(st)-O3(ob)
Error: Energy expression: cannot find parameters for bond: Si(st)-O1(ob)
Error: Energy expression: cannot find parameters for bond: Si(st)-O2(ob)
Error: Energy expression: cannot find parameters for bond: Al(ao)-O3(ob)
Error: Energy expression: cannot find parameters for bond: Al(ao)-O3(ob)
Error: Energy expression: cannot find parameters for bond: Al(ao)-OH(oh)
Error: Energy expression: cannot find parameters for bond: O1(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: OH(oh)-Al(ao)
Error: Energy expression: cannot find parameters for bond: O2(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O2(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O2(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O2(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O2(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O2(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O2(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O2(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O3(ob)-Al(ao)
Error: Energy expression: cannot find parameters for bond: O3(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O3(ob)-Al(ao)
Error: Energy expression: cannot find parameters for bond: O3(ob)-Al(ao)
Error: Energy expression: cannot find parameters for bond: O3(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O3(ob)-Al(ao)
Error: Energy expression: cannot find parameters for bond: O3(ob)-Al(ao)
Error: Energy expression: cannot find parameters for bond: O3(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O3(ob)-Al(ao)
Error: Energy expression: cannot find parameters for bond: O3(ob)-Al(ao)
Error: Energy expression: cannot find parameters for bond: Si(st)-O3(ob)
Error: Energy expression: cannot find parameters for bond: Si(st)-O1(ob)
Error: Energy expression: cannot find parameters for bond: Si(st)-O2(ob)
Error: Energy expression: cannot find parameters for bond: Si(st)-O3(ob)
Error: Energy expression: cannot find parameters for bond: Si(st)-O1(ob)
Error: Energy expression: cannot find parameters for bond: Si(st)-O2(ob)
Error: Energy expression: cannot find parameters for bond: Si(st)-O2(ob)
Error: Energy expression: cannot find parameters for bond: Si(st)-O3(ob)
Error: Energy expression: cannot find parameters for bond: Si(st)-O1(ob)
Error: Energy expression: cannot find parameters for bond: Si(st)-O2(ob)
Error: Energy expression: cannot find parameters for bond: Si(st)-O2(ob)
Error: Energy expression: cannot find parameters for bond: Si(st)-O2(ob)
Error: Energy expression: cannot find parameters for bond: Al(ao)-O3(ob)
Error: Energy expression: cannot find parameters for bond: Al(ao)-O3(ob)
Error: Energy expression: cannot find parameters for bond: Al(ao)-O3(ob)
Error: Energy expression: cannot find parameters for bond: Al(ao)-OH(oh)
Error: Energy expression: cannot find parameters for bond: Al(ao)-OH(oh)
Error: Energy expression: cannot find parameters for bond: Al(ao)-O3(ob)
Error: Energy expression: cannot find parameters for bond: Al(ao)-O3(ob)
Error: Energy expression: cannot find parameters for bond: Al(ao)-OH(oh)
Error: Energy expression: cannot find parameters for bond: O1(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O1(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: O1(ob)-Si(st)
Error: Energy expression: cannot find parameters for bond: OH(oh)-Al(ao)
Error: Energy expression: cannot find parameters for bond: OH(oh)-Al(ao)
Error: Energy expression: cannot find parameters for bond: OH(oh)-Al(ao)
while executing
"energy"
invoked from within
"if {![\$ee exists Atom.Gradient]} {
energy
}"
(procedure "vdWTailCorrection" line 55)
invoked from within
"vdWTailCorrection 9.50"
Total time used by DISCOVER: 0.20 secs
Completion date: Fri Jan 11 15:04:28 2013
Exiting Discover: An ERROR has occurred!
I understand that the force field is not finding the parameters for those bonds.
How could I surpass that?
Should I try Forcite. My objective is to get the entry parameters for a mesoscale calculation of a MMT + Starch + plastiscizers system
Does anyone could know what I have done wrong?
Thank you very much for your time
Best regards
Felipe Azevedo
