GROMOS is a force field for molecular dynamics simulation developed at the University of Groningen and at Computer-Aided Chemistry Group at the Laboratory for Physical Chemistry at the ETH Zurich.
The united atom force field was optimized with respect to the condensed phase properties of alkanes.
GROMOS is also the name for the molecular dynamics simulation package associated with this force field.
Aliphatic and aromatic hydrogen atoms were included implicitly by representing the carbon atom and attached hydrogen atoms as a single group centered on the carbon atom, a united atom force field. The van der Waals parameters were derived from calculation of the crystal structures of hydrocarbons and calculations on amino acids using short (0.8 nm) nonbonded cutoff radii.
A substantial rewrite of the simulation package was released in 1996. The force field was also improved, e.g. in the following way: aliphatic CHn groups were represented as united atoms with van der Waals interactions reparametrized on the basis of a series of molecular dynamics simulations of model liquid alkanes using long (1.4 nm) nonbonded cutoff radii. This version is continually being refined and a number of different parameter sets are available. GROMOS96, apart from having a study in molecular dynamics, also includes a study of stochastic dynamics and also of energy minimization. The energy minimization component was also part of the last GROMOS, named GROMOS87. GROMOS96 was planned and conceived during a time period of 20 months. This package is design within 40 different programs, and each of them have a different essential function. An example of two important programs within the GROMOS96 are PROGMT, in charge of constructing molecular topology and also PROPMT, changing the classical molecular topology into the path-integral molecular topology.
Land of treason-waste no reason-
we are breathing fire
We're packs of dogs-
we're enemies of men-we are not desired
Our face show-
we've grown cold-but
have not conspired
Old hearts gone-
the future's on-mother nations mired
I like a recepticle for the chosen dead,
we find our bodies clawed
And with the scent of death,
we find that we are not so very awed
Loyalties burned-
the words our blurred-overturn your own
Walk like dogs and watch the doors-
have your other stone
Stop the toys that match disordered-
calculate the thrones
Feel the pulse descending-
decaying hallowed tomes
In the starving sense you worship-
the nations of debris
You wear a cost of sewage-
that you've never ever seen
The time is now-the vicious here-
a stolen dinner code
The license of the savage land-
that you've always sold
So bite the hand that needs you
and bless another coal
The virus never issues-
from a cotton so very old
As the lights come down
You wash your hands and start to climb
the ladder that you stole
Slip the hatch-and spin the sword-
the money lords are poor
Push the tan-that rolls downhill-
their sense of dream absorbed
Still the cat that breaks the night-
tie him to the core
Chase the viruses that believe-
that what's right is scored
It's a senseless cash in of right for right-
what's wrong is never gone
And left is just a bassion for the fools