I am trying to do a simulation on Materials Studio that was performed on LAMMPS (doig2014).
It is about an adsorption of surfactant molecules onto solid surfaces, and the aim is to calculate the kinetic friction coefficient as a function of sliding velocity.
I got the Model done on Materials Studio: two surface (super cell) (100) of iron(III) oxide with lateral (xy) dimensions of 55.1 Å × 50.4 Å and a thickness of approximately 10 Å. First I cleaved the Fe2O3, and then I built a supercell using COMPASS forcefield and Conjugate Gradient algorithm; built an amorphous cell with 72 surfactants (stearic acid) and 168 squalanes, but when I try to optimize the geometry (forcite – compass) this error appear:
(…)
“Unable to calculate the ForcefieldType for particle 'FE'
The typing engine has been unable to assign a forcefield type.
No typing rules found that match (except the wildcard '?').
The typing engine has failed to calculate a forcefield type for 2464 particles.
Try using a different forcefield or assign types manually (and remember to turn off the automatic calculation of forcefield types).
Unable to calculate energy and gradients.
Geometry optimization finished with an error condition”
I change the algorithms, but this error still. When I changed the COMPASS to Universal, the type error changes:
“Automatic charge group calculation failed.
No charge groups have been calculated.
The particles that are being considered for a charge group are not charge neutral.
The absolute net charge is 0.8 and it should be less than 0.1
Unable to calculate energy and gradients.
Geometry optimization finished with an error condition.”
What is the problem?
i am also facing the same issue if you find the solution please let me know
thank you
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